diff --git a/pom.xml b/pom.xml
index 25b664e8ea..8067c84c28 100644
--- a/pom.xml
+++ b/pom.xml
@@ -110,12 +110,19 @@
 
 
     <dependencies>
-
         <dependency>
+            <groupId>com.google</groupId>
+            <artifactId>bitcoinj</artifactId>
+            <version>0.12-SNAPSHOT</version>
+        </dependency>
+
+        <!--
+         <dependency>
             <groupId>com.google</groupId>
             <artifactId>bitcoinj</artifactId>
             <version>0.11.3</version>
         </dependency>
+        -->
 
         <dependency>
             <groupId>net.tomp2p</groupId>
diff --git a/src/main/java/io/bitsquare/BitSquare.java b/src/main/java/io/bitsquare/BitSquare.java
index 6a2bc5f9b5..2e5980fcba 100644
--- a/src/main/java/io/bitsquare/BitSquare.java
+++ b/src/main/java/io/bitsquare/BitSquare.java
@@ -138,7 +138,9 @@ public class BitSquare extends Application
     private MenuBar getMenuBar()
     {
         MenuBar menuBar = new MenuBar();
-        menuBar.setUseSystemMenuBar(true);
+        // on mac we could placemenu bar in the systems menu
+        // menuBar.setUseSystemMenuBar(true);
+        menuBar.setUseSystemMenuBar(false);
 
         Menu fileMenu = new Menu("_File");
         fileMenu.setMnemonicParsing(true);
diff --git a/src/main/java/io/bitsquare/btc/AddressBasedCoinSelector.java b/src/main/java/io/bitsquare/btc/AddressBasedCoinSelector.java
index cdf8823e43..58628dad6f 100644
--- a/src/main/java/io/bitsquare/btc/AddressBasedCoinSelector.java
+++ b/src/main/java/io/bitsquare/btc/AddressBasedCoinSelector.java
@@ -6,10 +6,7 @@ import com.google.bitcoin.wallet.CoinSelection;
 import com.google.bitcoin.wallet.DefaultCoinSelector;
 import com.google.common.annotations.VisibleForTesting;
 import java.math.BigInteger;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.LinkedList;
+import java.util.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -45,38 +42,33 @@ class AddressBasedCoinSelector extends DefaultCoinSelector
     @VisibleForTesting
     static void sortOutputs(ArrayList<TransactionOutput> outputs)
     {
-        Collections.sort(outputs, (a, b) -> {
-            int depth1 = 0;
-            int depth2 = 0;
-            TransactionConfidence conf1 = a.getParentTransaction().getConfidence();
-            TransactionConfidence conf2 = b.getParentTransaction().getConfidence();
-            if (conf1.getConfidenceType() == TransactionConfidence.ConfidenceType.BUILDING)
+        Collections.sort(outputs, new Comparator<TransactionOutput>()
+        {
+            @Override
+            public int compare(TransactionOutput a, TransactionOutput b)
             {
-                depth1 = conf1.getDepthInBlocks();
+                int depth1 = 0;
+                int depth2 = 0;
+                TransactionConfidence conf1 = a.getParentTransaction().getConfidence();
+                TransactionConfidence conf2 = b.getParentTransaction().getConfidence();
+                if (conf1.getConfidenceType() == TransactionConfidence.ConfidenceType.BUILDING)
+                    depth1 = conf1.getDepthInBlocks();
+                if (conf2.getConfidenceType() == TransactionConfidence.ConfidenceType.BUILDING)
+                    depth2 = conf2.getDepthInBlocks();
+                Coin aValue = a.getValue();
+                Coin bValue = b.getValue();
+                BigInteger aCoinDepth = BigInteger.valueOf(aValue.value).multiply(BigInteger.valueOf(depth1));
+                BigInteger bCoinDepth = BigInteger.valueOf(bValue.value).multiply(BigInteger.valueOf(depth2));
+                int c1 = bCoinDepth.compareTo(aCoinDepth);
+                if (c1 != 0) return c1;
+                // The "coin*days" destroyed are equal, sort by value alone to get the lowest transaction size.
+                int c2 = bValue.compareTo(aValue);
+                if (c2 != 0) return c2;
+                // They are entirely equivalent (possibly pending) so sort by hash to ensure a total ordering.
+                BigInteger aHash = a.getParentTransaction().getHash().toBigInteger();
+                BigInteger bHash = b.getParentTransaction().getHash().toBigInteger();
+                return aHash.compareTo(bHash);
             }
-            if (conf2.getConfidenceType() == TransactionConfidence.ConfidenceType.BUILDING)
-            {
-                depth2 = conf2.getDepthInBlocks();
-            }
-            BigInteger aValue = a.getValue();
-            BigInteger bValue = b.getValue();
-            BigInteger aCoinDepth = aValue.multiply(BigInteger.valueOf(depth1));
-            BigInteger bCoinDepth = bValue.multiply(BigInteger.valueOf(depth2));
-            int c1 = bCoinDepth.compareTo(aCoinDepth);
-            if (c1 != 0)
-            {
-                return c1;
-            }
-            // The "coin*days" destroyed are equal, sort by value alone to get the lowest transaction size.
-            int c2 = bValue.compareTo(aValue);
-            if (c2 != 0)
-            {
-                return c2;
-            }
-            // They are entirely equivalent (possibly pending) so sort by hash to ensure a total ordering.
-            BigInteger aHash = a.getParentTransaction().getHash().toBigInteger();
-            BigInteger bHash = b.getParentTransaction().getHash().toBigInteger();
-            return aHash.compareTo(bHash);
         });
     }
 
@@ -129,7 +121,7 @@ class AddressBasedCoinSelector extends DefaultCoinSelector
     }
 
 
-    public CoinSelection select(BigInteger biTarget, LinkedList<TransactionOutput> candidates)
+    public CoinSelection select(Coin biTarget, LinkedList<TransactionOutput> candidates)
     {
         long target = biTarget.longValue();
         HashSet<TransactionOutput> selected = new HashSet<>();
@@ -163,7 +155,7 @@ class AddressBasedCoinSelector extends DefaultCoinSelector
         }
         // Total may be lower than target here, if the given candidates were insufficient to create to requested
         // transaction.
-        return new CoinSelection(BigInteger.valueOf(total), selected);
+        return new CoinSelection(Coin.valueOf(total), selected);
     }
 
     /*
diff --git a/src/main/java/io/bitsquare/btc/AddressEntry.java b/src/main/java/io/bitsquare/btc/AddressEntry.java
index 0f03f1510a..0e4770f2a4 100644
--- a/src/main/java/io/bitsquare/btc/AddressEntry.java
+++ b/src/main/java/io/bitsquare/btc/AddressEntry.java
@@ -1,25 +1,28 @@
 package io.bitsquare.btc;
 
 import com.google.bitcoin.core.Address;
-import com.google.bitcoin.core.ECKey;
 import com.google.bitcoin.core.NetworkParameters;
 import com.google.bitcoin.core.Utils;
+import com.google.bitcoin.crypto.DeterministicKey;
 import java.io.Serializable;
 
 public class AddressEntry implements Serializable
 {
     private static final long serialVersionUID = 5501603992599920416L;
-    private final ECKey key;
+    private transient DeterministicKey key;
     private final NetworkParameters params;
     private final AddressContext addressContext;
+    private final byte[] pubKeyHash;
 
     private String tradeId = null;
 
-    public AddressEntry(ECKey key, NetworkParameters params, AddressContext addressContext)
+    public AddressEntry(DeterministicKey key, NetworkParameters params, AddressContext addressContext)
     {
         this.key = key;
         this.params = params;
         this.addressContext = addressContext;
+
+        pubKeyHash = key.getPubOnly().getPubKeyHash();
     }
 
 
@@ -45,10 +48,10 @@ public class AddressEntry implements Serializable
 
     public String getPubKeyAsHexString()
     {
-        return Utils.bytesToHexString(key.getPubKey());
+        return Utils.HEX.encode(key.getPubKey());
     }
 
-    public ECKey getKey()
+    public DeterministicKey getKey()
     {
         return key;
     }
@@ -58,6 +61,16 @@ public class AddressEntry implements Serializable
         return key.toAddress(params);
     }
 
+    public void setDeterministicKey(DeterministicKey key)
+    {
+        this.key = key;
+    }
+
+    public byte[] getPubKeyHash()
+    {
+        return pubKeyHash;
+    }
+
     public static enum AddressContext
     {
         REGISTRATION_FEE,
diff --git a/src/main/java/io/bitsquare/btc/BitSquareWallet.java b/src/main/java/io/bitsquare/btc/BitSquareWallet.java
deleted file mode 100644
index cbcc1d4621..0000000000
--- a/src/main/java/io/bitsquare/btc/BitSquareWallet.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package io.bitsquare.btc;
-
-import com.google.bitcoin.core.NetworkParameters;
-import com.google.bitcoin.core.Wallet;
-import com.google.bitcoin.crypto.KeyCrypter;
-import java.io.Serializable;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-class BitSquareWallet extends Wallet implements Serializable
-{
-    private static final Logger log = LoggerFactory.getLogger(BitSquareWallet.class);
-    private static final long serialVersionUID = -6231929674475881549L;
-
-    public BitSquareWallet(NetworkParameters params)
-    {
-        super(params);
-    }
-
-    private BitSquareWallet(NetworkParameters params, KeyCrypter keyCrypter)
-    {
-        super(params, keyCrypter);
-    }
-
-}
diff --git a/src/main/java/io/bitsquare/btc/BitSquareWalletAppKit.java b/src/main/java/io/bitsquare/btc/BitSquareWalletAppKit.java
deleted file mode 100644
index ea5a990317..0000000000
--- a/src/main/java/io/bitsquare/btc/BitSquareWalletAppKit.java
+++ /dev/null
@@ -1,171 +0,0 @@
-package io.bitsquare.btc;
-
-import com.google.bitcoin.core.*;
-import com.google.bitcoin.kits.WalletAppKit;
-import com.google.bitcoin.net.discovery.DnsDiscovery;
-import com.google.bitcoin.store.BlockStoreException;
-import com.google.bitcoin.store.SPVBlockStore;
-import com.google.bitcoin.store.WalletProtobufSerializer;
-import com.google.common.util.concurrent.FutureCallback;
-import com.google.common.util.concurrent.Futures;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.IOException;
-import java.util.concurrent.TimeUnit;
-
-public class BitSquareWalletAppKit extends WalletAppKit
-{
-
-    public BitSquareWalletAppKit(NetworkParameters params, File directory)
-    {
-        super(params, directory, WalletFacade.WALLET_PREFIX);
-    }
-
-    @Override
-    protected void startUp() throws Exception
-    {
-        // Runs in a separate thread.
-        if (!directory.exists())
-        {
-            if (!directory.mkdir())
-            {
-                throw new IOException("Could not create named directory " + directory.getCanonicalPath());
-            }
-        }
-        FileInputStream walletStream = null;
-        try
-        {
-            File chainFile = new File(directory, filePrefix + ".spvchain");
-            boolean chainFileExists = chainFile.exists();
-            vWalletFile = new File(directory, filePrefix + ".wallet");
-            boolean shouldReplayWallet = vWalletFile.exists() && !chainFileExists;
-
-            vStore = new SPVBlockStore(params, chainFile);
-            if (!chainFileExists && checkpoints != null)
-            {
-                // Ugly hack! We have to create the wallet once here to learn the earliest key time, and then throw it
-                // away. The reason is that wallet extensions might need access to peergroups/chains/etc so we have to
-                // create the wallet later, but we need to know the time early here before we create the BlockChain
-                // object.
-                long time = Long.MAX_VALUE;
-                if (vWalletFile.exists())
-                {
-                    Wallet wallet = new BitSquareWallet(params);
-                    FileInputStream stream = new FileInputStream(vWalletFile);
-                    new WalletProtobufSerializer().readWallet(WalletProtobufSerializer.parseToProto(stream), wallet);
-                    time = wallet.getEarliestKeyCreationTime();
-                }
-                CheckpointManager.checkpoint(params, checkpoints, vStore, time);
-            }
-            vChain = new BlockChain(params, vStore);
-            vPeerGroup = createPeerGroup();
-
-            vPeerGroup.setBloomFilterFalsePositiveRate(0.001);  // 0,1% instead of default 0,05%
-
-            if (this.userAgent != null)
-            {
-                vPeerGroup.setUserAgent(userAgent, version);
-            }
-            if (vWalletFile.exists())
-            {
-                walletStream = new FileInputStream(vWalletFile);
-                vWallet = new BitSquareWallet(params);
-                addWalletExtensions(); // All extensions must be present before we deserialize
-                new WalletProtobufSerializer().readWallet(WalletProtobufSerializer.parseToProto(walletStream), vWallet);
-                if (shouldReplayWallet)
-                {
-                    vWallet.clearTransactions(0);
-                }
-            }
-            else
-            {
-                vWallet = new BitSquareWallet(params);
-                vWallet.addKey(new ECKey());
-                addWalletExtensions();
-            }
-            if (useAutoSave)
-            {
-                vWallet.autosaveToFile(vWalletFile, 1, TimeUnit.SECONDS, null);
-            }
-            // Set up peer addresses or discovery first, so if wallet extensions try to broadcast a transaction
-            // before we're actually connected the broadcast waits for an appropriate number of connections.
-            if (peerAddresses != null)
-            {
-                for (PeerAddress addr : peerAddresses)
-                {
-                    vPeerGroup.addAddress(addr);
-                }
-                peerAddresses = null;
-            }
-            else
-            {
-                vPeerGroup.addPeerDiscovery(new DnsDiscovery(params));
-            }
-            vChain.addWallet(vWallet);
-            vPeerGroup.addWallet(vWallet);
-            onSetupCompleted();
-
-            if (blockingStartup)
-            {
-                vPeerGroup.startAsync();
-                vPeerGroup.awaitRunning();
-                // Make sure we shut down cleanly.
-                installShutdownHook();
-                // TODO: Be able to use the provided download listener when doing a blocking startup.
-                final DownloadListener listener = new DownloadListener();
-                vPeerGroup.startBlockChainDownload(listener);
-                listener.await();
-            }
-            else
-            {
-                //TODO deprecated
-                Futures.addCallback(vPeerGroup.start(), new FutureCallback<State>()
-                {
-                    @Override
-                    public void onSuccess(State result)
-                    {
-                        final PeerEventListener l = downloadListener == null ? new DownloadListener() : downloadListener;
-                        vPeerGroup.startBlockChainDownload(l);
-                    }
-
-                    @Override
-                    public void onFailure(Throwable t)
-                    {
-                        throw new RuntimeException(t);
-                    }
-                });
-            }
-        } catch (BlockStoreException e)
-        {
-            throw new IOException(e);
-        } finally
-        {
-            if (walletStream != null)
-            {
-                walletStream.close();
-            }
-        }
-    }
-
-    private void installShutdownHook()
-    {
-        if (autoStop)
-        {
-            Runtime.getRuntime().addShutdownHook(new Thread()
-            {
-                @Override
-                public void run()
-                {
-                    try
-                    {
-                        BitSquareWalletAppKit.this.stopAsync();
-
-                    } catch (Exception e)
-                    {
-                        throw new RuntimeException(e);
-                    }
-                }
-            });
-        }
-    }
-}
diff --git a/src/main/java/io/bitsquare/btc/BtcFormatter.java b/src/main/java/io/bitsquare/btc/BtcFormatter.java
deleted file mode 100644
index 6763e5331c..0000000000
--- a/src/main/java/io/bitsquare/btc/BtcFormatter.java
+++ /dev/null
@@ -1,59 +0,0 @@
-package io.bitsquare.btc;
-
-import com.google.bitcoin.core.Utils;
-import io.bitsquare.gui.util.BitSquareConverter;
-import java.math.BigInteger;
-import java.text.DecimalFormat;
-import java.util.Locale;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-// TODO
-public class BtcFormatter
-{
-    private static final BigInteger BTC = new BigInteger("100000000");
-    private static final Logger log = LoggerFactory.getLogger(BtcFormatter.class);
-
-    public static BigInteger mBTC = new BigInteger("100000");
-
-
-    public static String formatSatoshis(BigInteger value)
-    {
-        return Utils.bitcoinValueToFriendlyString(value);
-    }
-
-    //TODO
-    public static double satoshiToBTC(BigInteger satoshis)
-    {
-        return satoshis.doubleValue() / BTC.doubleValue();
-    }
-
-    public static BigInteger stringValueToSatoshis(String value)
-    {
-        try
-        {
-            return Utils.toNanoCoins(String.valueOf(BitSquareConverter.stringToDouble(value)));
-        } catch (ArithmeticException e)
-        {
-            log.warn("ArithmeticException " + e);
-        }
-        return BigInteger.ZERO;
-    }
-
-    public static BigInteger doubleValueToSatoshis(double value)
-    {
-        try
-        {
-            // only "." as decimal sep supported by Utils.toNanoCoins
-            final DecimalFormat decimalFormat = (DecimalFormat) DecimalFormat.getInstance(Locale.ENGLISH);
-            decimalFormat.setMaximumFractionDigits(10);
-            decimalFormat.setMinimumFractionDigits(10);
-            String stringValue = decimalFormat.format(value);
-            return Utils.toNanoCoins(stringValue);
-        } catch (Exception e)
-        {
-            log.warn("Exception at doubleValueToSatoshis " + e.getMessage());
-            return BigInteger.ZERO;
-        }
-    }
-}
diff --git a/src/main/java/io/bitsquare/btc/BtcValidator.java b/src/main/java/io/bitsquare/btc/BtcValidator.java
index 2fd5388ced..c242439baa 100644
--- a/src/main/java/io/bitsquare/btc/BtcValidator.java
+++ b/src/main/java/io/bitsquare/btc/BtcValidator.java
@@ -1,10 +1,8 @@
 package io.bitsquare.btc;
 
-import com.google.bitcoin.core.Address;
-import com.google.bitcoin.core.AddressFormatException;
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.NetworkParameters;
 import com.google.bitcoin.core.Transaction;
-import java.math.BigInteger;
 import javax.inject.Inject;
 
 public class BtcValidator
@@ -17,12 +15,12 @@ public class BtcValidator
         BtcValidator.params = params;
     }
 
-    public static boolean isMinSpendableAmount(BigInteger amount)
+    public static boolean isMinSpendableAmount(Coin amount)
     {
         return amount != null && amount.compareTo(FeePolicy.TX_FEE.add(Transaction.MIN_NONDUST_OUTPUT)) > 0;
     }
 
-    public boolean isAddressValid(String addressString)
+   /* public boolean isAddressValid(String addressString)
     {
         try
         {
@@ -32,6 +30,6 @@ public class BtcValidator
         {
             return false;
         }
-    }
+    } */
 
 }
diff --git a/src/main/java/io/bitsquare/btc/FeePolicy.java b/src/main/java/io/bitsquare/btc/FeePolicy.java
index eb1a8d72f9..d7a0bb0e8e 100644
--- a/src/main/java/io/bitsquare/btc/FeePolicy.java
+++ b/src/main/java/io/bitsquare/btc/FeePolicy.java
@@ -1,17 +1,16 @@
 package io.bitsquare.btc;
 
 import com.google.bitcoin.core.*;
-import java.math.BigInteger;
 import javax.inject.Inject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class FeePolicy
 {
-    public static final BigInteger TX_FEE = Transaction.REFERENCE_DEFAULT_MIN_TX_FEE;
-    public static final BigInteger ACCOUNT_REGISTRATION_FEE = Utils.toNanoCoins("0.01");
-    public static final BigInteger CREATE_OFFER_FEE = Utils.toNanoCoins("0.001");
-    public static final BigInteger TAKE_OFFER_FEE = CREATE_OFFER_FEE;
+    public static final Coin TX_FEE = Transaction.REFERENCE_DEFAULT_MIN_TX_FEE;
+    public static final Coin ACCOUNT_REGISTRATION_FEE = Coin.CENT; // 0.01
+    public static final Coin CREATE_OFFER_FEE = Coin.MILLICOIN; // 0.001
+    public static final Coin TAKE_OFFER_FEE = CREATE_OFFER_FEE;
     private static final Logger log = LoggerFactory.getLogger(FeePolicy.class);
     private static final String registrationFeeAddress = "mvkDXt4QmN4Nq9dRUsRigBCaovde9nLkZR";
     private static final String createOfferFeeAddress = "n2upbsaKAe4PD3cc4JfS7UCqPC5oNd7Ckg";
diff --git a/src/main/java/io/bitsquare/btc/WalletFacade.java b/src/main/java/io/bitsquare/btc/WalletFacade.java
index aa7a4e22ae..4752ece02f 100644
--- a/src/main/java/io/bitsquare/btc/WalletFacade.java
+++ b/src/main/java/io/bitsquare/btc/WalletFacade.java
@@ -1,7 +1,9 @@
 package io.bitsquare.btc;
 
 import com.google.bitcoin.core.*;
+import com.google.bitcoin.crypto.DeterministicKey;
 import com.google.bitcoin.crypto.TransactionSignature;
+import com.google.bitcoin.kits.WalletAppKit;
 import com.google.bitcoin.params.MainNetParams;
 import com.google.bitcoin.params.RegTestParams;
 import com.google.bitcoin.script.Script;
@@ -18,6 +20,7 @@ import io.bitsquare.btc.listeners.BalanceListener;
 import io.bitsquare.btc.listeners.ConfidenceListener;
 import io.bitsquare.crypto.CryptoFacade;
 import io.bitsquare.storage.Persistence;
+import io.bitsquare.util.StorageDirectory;
 import java.io.Serializable;
 import java.math.BigInteger;
 import java.util.*;
@@ -30,10 +33,9 @@ import javax.inject.Inject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import static com.google.bitcoin.script.ScriptOpCodes.OP_RETURN;
-
 /**
  * TODO: use walletextension (with protobuffer) instead of saving addressEntryList via storage
+ * TODO: use HD wallet features instead of addressEntryList
  */
 public class WalletFacade
 {
@@ -49,14 +51,14 @@ public class WalletFacade
 
 
     private final NetworkParameters params;
-    private final BitSquareWalletAppKit walletAppKit;
+    private WalletAppKit walletAppKit;
     private final FeePolicy feePolicy;
     private final CryptoFacade cryptoFacade;
     private final Persistence persistence;
     private final List<DownloadListener> downloadListeners = new ArrayList<>();
     private final List<ConfidenceListener> confidenceListeners = new ArrayList<>();
     private final List<BalanceListener> balanceListeners = new ArrayList<>();
-    private BitSquareWallet wallet;
+    private Wallet wallet;
     private WalletEventListener walletEventListener;
 
     @GuardedBy("lock")
@@ -67,10 +69,9 @@ public class WalletFacade
     ///////////////////////////////////////////////////////////////////////////////////////////
 
     @Inject
-    public WalletFacade(NetworkParameters params, BitSquareWalletAppKit walletAppKit, FeePolicy feePolicy, CryptoFacade cryptoFacade, Persistence persistence)
+    public WalletFacade(NetworkParameters params, FeePolicy feePolicy, CryptoFacade cryptoFacade, Persistence persistence)
     {
         this.params = params;
-        this.walletAppKit = walletAppKit;
         this.feePolicy = feePolicy;
         this.cryptoFacade = cryptoFacade;
         this.persistence = persistence;
@@ -81,7 +82,7 @@ public class WalletFacade
     // Public Methods
     ///////////////////////////////////////////////////////////////////////////////////////////
 
-    public void initWallet()
+    public void initialize(StartupListener startupListener)
     {
         // Tell bitcoinj to execute event handlers on the JavaFX UI thread. This keeps things simple and means
         // we cannot forget to switch threads when adding event handlers. Unfortunately, the DownloadListener
@@ -89,9 +90,27 @@ public class WalletFacade
         // a future version.
         Threading.USER_THREAD = Platform::runLater;
 
+        // If seed is non-null it means we are restoring from backup.
+        walletAppKit = new WalletAppKit(params, StorageDirectory.getStorageDirectory(), WALLET_PREFIX)
+        {
+            @Override
+            protected void onSetupCompleted()
+            {
+                // Don't make the user wait for confirmations for now, as the intention is they're sending it
+                // their own money!
+                walletAppKit.wallet().allowSpendingUnconfirmedTransactions();
+                if (params != RegTestParams.get())
+                    walletAppKit.peerGroup().setMaxConnections(11);
+                walletAppKit.peerGroup().setBloomFilterFalsePositiveRate(0.00001);
+                initWallet();
+                Platform.runLater(startupListener::completed);
+            }
+        };
+        // Now configure and start the appkit. This will take a second or two - we could show a temporary splash screen
+        // or progress widget to keep the user engaged whilst we initialise, but we don't.
         if (params == RegTestParams.get())
         {
-            walletAppKit.connectToLocalHost();   // You should execute a regtest mode bitcoind locally.
+            walletAppKit.connectToLocalHost();   // You should run a regtest mode bitcoind locally.
         }
         else if (params == MainNetParams.get())
         {
@@ -99,23 +118,21 @@ public class WalletFacade
             // in the checkpoints file and then download the rest from the network. It makes things much faster.
             // Checkpoint files are made using the BuildCheckpoints tool and usually we have to download the
             // last months worth or more (takes a few seconds).
-            walletAppKit.setCheckpoints(getClass().getResourceAsStream("/wallet/checkpoints"));
+            walletAppKit.setCheckpoints(getClass().getResourceAsStream("checkpoints"));
+            // As an example!
+            // walletAppKit.useTor();
         }
+        walletAppKit.setDownloadListener(new BlockChainDownloadListener())
+                    .setBlockingStartup(false)
+                    .restoreWalletFromSeed(null)
+                    .setUserAgent("BitSquare", "0.1");
 
-        walletAppKit.setAutoSave(true);
-
-        // add well known stable nodes
-        //walletAppKit.peerGroup().addAddress();
-
-        // Now configure and start the appkit. This will take a second or two - we could show a temporary splash screen
-        // or progress widget to keep the user engaged whilst we initialise, but we don't.
-        walletAppKit.setDownloadListener(new BlockChainDownloadListener());
-        walletAppKit.setBlockingStartup(false);
-        walletAppKit.setUserAgent("BitSquare", "0.1");
         walletAppKit.startAsync();
-        walletAppKit.awaitRunning();
+    }
 
-        wallet = (BitSquareWallet) walletAppKit.wallet();
+    private void initWallet()
+    {
+        wallet = walletAppKit.wallet();
 
         wallet.allowSpendingUnconfirmedTransactions();
         //walletAppKit.peerGroup().setMaxConnections(11);
@@ -127,45 +144,48 @@ public class WalletFacade
        /* else
             walletAppKit.peerGroup().setMinBroadcastConnections(2);  */
 
-
         walletEventListener = new WalletEventListener()
         {
             @Override
-            public void onCoinsReceived(Wallet wallet, Transaction tx, BigInteger prevBalance, BigInteger newBalance)
+            public void onCoinsReceived(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance)
             {
                 notifyBalanceListeners();
             }
 
+            @Override
+            public void onCoinsSent(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance)
+            {
+                notifyBalanceListeners();
+            }
+
+            @Override
+            public void onReorganize(Wallet wallet)
+            {
+
+            }
+
             @Override
             public void onTransactionConfidenceChanged(Wallet wallet, Transaction tx)
             {
                 notifyConfidenceListeners(tx);
             }
 
-            @Override
-            public void onCoinsSent(Wallet wallet, Transaction tx, BigInteger prevBalance, BigInteger newBalance)
-            {
-                notifyBalanceListeners();
-            }
-
-            @Override
-            public void onReorganize(Wallet wallet)
-            {
-            }
-
             @Override
             public void onWalletChanged(Wallet wallet)
             {
-            }
 
-            @Override
-            public void onKeysAdded(Wallet wallet, List<ECKey> keys)
-            {
             }
 
             @Override
             public void onScriptsAdded(Wallet wallet, List<Script> scripts)
             {
+
+            }
+
+            @Override
+            public void onKeysAdded(List<ECKey> keys)
+            {
+
             }
         };
         wallet.addEventListener(walletEventListener);
@@ -174,12 +194,16 @@ public class WalletFacade
         List<AddressEntry> persistedAddressEntryList = (List<AddressEntry>) serializable;
         if (serializable instanceof List)
         {
+            for (AddressEntry persistedAddressEntry : persistedAddressEntryList)
+            {
+                persistedAddressEntry.setDeterministicKey((DeterministicKey) wallet.findKeyFromPubHash(persistedAddressEntry.getPubKeyHash()));
+            }
             addressEntryList = persistedAddressEntryList;
         }
         else
         {
             lock.lock();
-            ECKey registrationKey = wallet.getKeys().get(0);
+            DeterministicKey registrationKey = wallet.currentReceiveKey();
             addressEntryList.add(new AddressEntry(registrationKey, params, AddressEntry.AddressContext.REGISTRATION_FEE));
             lock.unlock();
             saveAddressInfoList();
@@ -330,9 +354,8 @@ public class WalletFacade
     {
         lock.lock();
         wallet.getLock().lock();
-        ECKey key = new ECKey();
-        wallet.addKey(key);
-        wallet.addWatchedAddress(key.toAddress(params));
+
+        DeterministicKey key = wallet.freshReceiveKey();
         AddressEntry addressEntry = new AddressEntry(key, params, addressContext);
         addressEntryList.add(addressEntry);
         saveAddressInfoList();
@@ -483,14 +506,14 @@ public class WalletFacade
     // Balance
     ///////////////////////////////////////////////////////////////////////////////////////////
 
-    public BigInteger getBalanceForAddress(Address address)
+    public Coin getBalanceForAddress(Address address)
     {
         return getBalance(wallet.calculateAllSpendCandidates(true), address);
     }
 
-    private BigInteger getBalance(LinkedList<TransactionOutput> transactionOutputs, Address address)
+    private Coin getBalance(LinkedList<TransactionOutput> transactionOutputs, Address address)
     {
-        BigInteger balance = BigInteger.ZERO;
+        Coin balance = Coin.ZERO;
         for (TransactionOutput transactionOutput : transactionOutputs)
         {
             if (transactionOutput.getScriptPubKey().isSentToAddress() || transactionOutput.getScriptPubKey().isSentToP2SH())
@@ -509,7 +532,7 @@ public class WalletFacade
     {
         for (BalanceListener balanceListener : balanceListeners)
         {
-            BigInteger balance;
+            Coin balance;
             if (balanceListener.getAddress() != null)
             {
                 balance = getBalanceForAddress(balanceListener.getAddress());
@@ -523,24 +546,24 @@ public class WalletFacade
         }
     }
 
-    public BigInteger getWalletBalance()
+    public Coin getWalletBalance()
     {
         return wallet.getBalance(Wallet.BalanceType.ESTIMATED);
     }
 
-    BigInteger getRegistrationBalance()
+    Coin getRegistrationBalance()
     {
         return getBalanceForAddress(getRegistrationAddressInfo().getAddress());
     }
 
-    public BigInteger getArbitratorDepositBalance()
+    public Coin getArbitratorDepositBalance()
     {
         return getBalanceForAddress(getArbitratorDepositAddressInfo().getAddress());
     }
 
     public boolean isRegistrationFeeBalanceNonZero()
     {
-        return getRegistrationBalance().compareTo(BigInteger.ZERO) > 0;
+        return getRegistrationBalance().compareTo(Coin.ZERO) > 0;
     }
 
     public boolean isRegistrationFeeBalanceSufficient()
@@ -551,14 +574,14 @@ public class WalletFacade
     public boolean isUnusedTradeAddressBalanceAboveCreationFee()
     {
         AddressEntry unUsedAddressEntry = getUnusedTradeAddressInfo();
-        BigInteger unUsedAddressInfoBalance = getBalanceForAddress(unUsedAddressEntry.getAddress());
+        Coin unUsedAddressInfoBalance = getBalanceForAddress(unUsedAddressEntry.getAddress());
         return unUsedAddressInfoBalance.compareTo(FeePolicy.CREATE_OFFER_FEE) > 0;
     }
 
     public boolean isUnusedTradeAddressBalanceAboveTakeOfferFee()
     {
         AddressEntry unUsedAddressEntry = getUnusedTradeAddressInfo();
-        BigInteger unUsedAddressInfoBalance = getBalanceForAddress(unUsedAddressEntry.getAddress());
+        Coin unUsedAddressInfoBalance = getBalanceForAddress(unUsedAddressEntry.getAddress());
         return unUsedAddressInfoBalance.compareTo(FeePolicy.TAKE_OFFER_FEE) > 0;
     }
 
@@ -582,11 +605,12 @@ public class WalletFacade
 
         Transaction tx = new Transaction(params);
 
-        byte[] data = cryptoFacade.getEmbeddedAccountRegistrationData(getRegistrationAddressInfo().getKey(), stringifiedBankAccounts);
-        tx.addOutput(Transaction.MIN_NONDUST_OUTPUT, new ScriptBuilder().op(OP_RETURN).data(data).build());
+        //TODO priv key is null, use other signing key or find out why it is null at that moment
+        //byte[] data = cryptoFacade.getEmbeddedAccountRegistrationData(getRegistrationAddressInfo().getKey(), stringifiedBankAccounts);
+        //tx.addOutput(Transaction.MIN_NONDUST_OUTPUT, new ScriptBuilder().op(OP_RETURN).data(data).build());
 
-        BigInteger fee = FeePolicy.ACCOUNT_REGISTRATION_FEE.subtract(Transaction.MIN_NONDUST_OUTPUT).subtract(FeePolicy.TX_FEE);
-        log.trace("fee: " + BtcFormatter.formatSatoshis(fee));
+        Coin fee = FeePolicy.ACCOUNT_REGISTRATION_FEE.subtract(Transaction.MIN_NONDUST_OUTPUT).subtract(FeePolicy.TX_FEE);
+        log.trace("fee: " + fee.toFriendlyString());
         tx.addOutput(fee, feePolicy.getAddressForRegistrationFee());
 
         Wallet.SendRequest sendRequest = Wallet.SendRequest.forTx(tx);
@@ -595,7 +619,21 @@ public class WalletFacade
         sendRequest.coinSelector = new AddressBasedCoinSelector(params, getRegistrationAddressInfo(), false);
         sendRequest.changeAddress = getRegistrationAddressInfo().getAddress();
         Wallet.SendResult sendResult = wallet.sendCoins(sendRequest);
+        //Object k = getRegistrationAddressInfo().getKey();
         Futures.addCallback(sendResult.broadcastComplete, callback);
+        /*Futures.addCallback(sendResult.broadcastComplete, new FutureCallback<Transaction>(){
+            @Override
+            public void onSuccess(@Nullable Transaction result)
+            {
+                Object k = getRegistrationAddressInfo().getKey();
+            }
+
+            @Override
+            public void onFailure(Throwable t)
+            {
+
+            }
+        }); */
 
         log.debug("Registration transaction: " + tx);
         printInputs("payRegistrationFee", tx);
@@ -604,8 +642,8 @@ public class WalletFacade
     public String payCreateOfferFee(String offerId, FutureCallback<Transaction> callback) throws InsufficientMoneyException
     {
         Transaction tx = new Transaction(params);
-        BigInteger fee = FeePolicy.CREATE_OFFER_FEE.subtract(FeePolicy.TX_FEE);
-        log.trace("fee: " + BtcFormatter.formatSatoshis(fee));
+        Coin fee = FeePolicy.CREATE_OFFER_FEE.subtract(FeePolicy.TX_FEE);
+        log.trace("fee: " + fee.toFriendlyString());
         tx.addOutput(fee, feePolicy.getAddressForCreateOfferFee());
 
         Wallet.SendRequest sendRequest = Wallet.SendRequest.forTx(tx);
@@ -625,8 +663,8 @@ public class WalletFacade
     public String payTakeOfferFee(String offerId, FutureCallback<Transaction> callback) throws InsufficientMoneyException
     {
         Transaction tx = new Transaction(params);
-        BigInteger fee = FeePolicy.TAKE_OFFER_FEE.subtract(FeePolicy.TX_FEE);
-        log.trace("fee: " + BtcFormatter.formatSatoshis(fee));
+        Coin fee = FeePolicy.TAKE_OFFER_FEE.subtract(FeePolicy.TX_FEE);
+        log.trace("fee: " + fee.toFriendlyString());
         tx.addOutput(fee, feePolicy.getAddressForTakeOfferFee());
 
         Wallet.SendRequest sendRequest = Wallet.SendRequest.forTx(tx);
@@ -651,7 +689,7 @@ public class WalletFacade
     public String sendFunds(String withdrawFromAddress,
                             String withdrawToAddress,
                             String changeAddress,
-                            BigInteger amount,
+                            Coin amount,
                             FutureCallback<Transaction> callback) throws AddressFormatException, InsufficientMoneyException, IllegalArgumentException
     {
         Transaction tx = new Transaction(params);
@@ -673,7 +711,7 @@ public class WalletFacade
     }
 
 
-    // TODO: Trade process - use P2SH instead and optimize data exchange
+    // TODO: Trade process - use P2SH instead and optimize tx creation and data exchange
 
     ///////////////////////////////////////////////////////////////////////////////////////////
     // Trade process
@@ -682,7 +720,7 @@ public class WalletFacade
     // 1. step: deposit tx
     // Offerer creates the 2of3 multiSig deposit tx with his unsigned input and change output
 
-    public Transaction offererCreatesMSTxAndAddPayment(BigInteger offererInputAmount,
+    public Transaction offererCreatesMSTxAndAddPayment(Coin offererInputAmount,
                                                        String offererPubKey,
                                                        String takerPubKey,
                                                        String arbitratorPubKey,
@@ -690,15 +728,15 @@ public class WalletFacade
     {
         log.debug("offererCreatesMSTxAndAddPayment");
         log.trace("inputs: ");
-        log.trace("offererInputAmount=" + BtcFormatter.formatSatoshis(offererInputAmount));
+        log.trace("offererInputAmount=" + offererInputAmount.toFriendlyString());
         log.trace("offererPubKey=" + offererPubKey);
         log.trace("takerPubKey=" + takerPubKey);
         log.trace("arbitratorPubKey=" + arbitratorPubKey);
-        log.trace("offererInputAmount=" + BtcFormatter.formatSatoshis(offererInputAmount));
+        log.trace("offererInputAmount=" + offererInputAmount.toFriendlyString());
 
         // we need to subtract the fee as it will go to the miners
-        BigInteger amountToPay = offererInputAmount.subtract(FeePolicy.TX_FEE);
-        log.trace("amountToPay=" + BtcFormatter.formatSatoshis(amountToPay));
+        Coin amountToPay = offererInputAmount.subtract(FeePolicy.TX_FEE);
+        log.trace("amountToPay=" + amountToPay.toFriendlyString());
 
         // We pay the offererInputAmount to a temporary MS output which will be changed later to the correct value.
         // With the usage of completeTx() we get all the work done with fee calculation, validation and coin selection.
@@ -742,8 +780,8 @@ public class WalletFacade
     // 2. step: deposit tx
     // Taker adds his input and change output, changes the multiSig amount to the correct value and sign his input
 
-    public Transaction takerAddPaymentAndSignTx(BigInteger takerInputAmount,
-                                                BigInteger msOutputAmount,
+    public Transaction takerAddPaymentAndSignTx(Coin takerInputAmount,
+                                                Coin msOutputAmount,
                                                 String offererPubKey,
                                                 String takerPubKey,
                                                 String arbitratorPubKey,
@@ -752,8 +790,8 @@ public class WalletFacade
     {
         log.debug("takerAddPaymentAndSignTx");
         log.trace("inputs: ");
-        log.trace("takerInputAmount=" + BtcFormatter.formatSatoshis(takerInputAmount));
-        log.trace("msOutputAmount=" + BtcFormatter.formatSatoshis(msOutputAmount));
+        log.trace("takerInputAmount=" + takerInputAmount.toFriendlyString());
+        log.trace("msOutputAmount=" + msOutputAmount.toFriendlyString());
         log.trace("offererPubKey=" + offererPubKey);
         log.trace("takerPubKey=" + takerPubKey);
         log.trace("arbitratorPubKey=" + arbitratorPubKey);
@@ -1017,21 +1055,21 @@ public class WalletFacade
     // 5. step payout tx: Offerer creates payout tx and signs it
 
     public Pair<ECKey.ECDSASignature, String> offererCreatesAndSignsPayoutTx(String depositTxID,
-                                                                             BigInteger offererPaybackAmount,
-                                                                             BigInteger takerPaybackAmount,
+                                                                             Coin offererPaybackAmount,
+                                                                             Coin takerPaybackAmount,
                                                                              String takerAddress,
                                                                              String tradeID) throws AddressFormatException
     {
         log.debug("offererCreatesAndSignsPayoutTx");
         log.trace("inputs: ");
         log.trace("depositTxID=" + depositTxID);
-        log.trace("offererPaybackAmount=" + BtcFormatter.formatSatoshis(offererPaybackAmount));
-        log.trace("takerPaybackAmount=" + BtcFormatter.formatSatoshis(takerPaybackAmount));
+        log.trace("offererPaybackAmount=" + offererPaybackAmount.toFriendlyString());
+        log.trace("takerPaybackAmount=" + takerPaybackAmount.toFriendlyString());
         log.trace("takerAddress=" + takerAddress);
 
         // Offerer has published depositTx earlier, so he has it in his wallet
         Transaction depositTx = wallet.getTransaction(new Sha256Hash(depositTxID));
-        String depositTxAsHex = Utils.bytesToHexString(depositTx.bitcoinSerialize());
+        String depositTxAsHex = Utils.HEX.encode(depositTx.bitcoinSerialize());
 
         // We create the payout tx
         Transaction tx = createPayoutTx(depositTxAsHex, offererPaybackAmount, takerPaybackAmount, getAddressInfoByTradeID(tradeID).getAddressString(), takerAddress);
@@ -1054,8 +1092,8 @@ public class WalletFacade
     public void takerSignsAndSendsTx(String depositTxAsHex,
                                      String offererSignatureR,
                                      String offererSignatureS,
-                                     BigInteger offererPaybackAmount,
-                                     BigInteger takerPaybackAmount,
+                                     Coin offererPaybackAmount,
+                                     Coin takerPaybackAmount,
                                      String offererAddress,
                                      String tradeID,
                                      FutureCallback<Transaction> callback) throws AddressFormatException
@@ -1065,8 +1103,8 @@ public class WalletFacade
         log.trace("depositTxAsHex=" + depositTxAsHex);
         log.trace("offererSignatureR=" + offererSignatureR);
         log.trace("offererSignatureS=" + offererSignatureS);
-        log.trace("offererPaybackAmount=" + BtcFormatter.formatSatoshis(offererPaybackAmount));
-        log.trace("takerPaybackAmount=" + BtcFormatter.formatSatoshis(takerPaybackAmount));
+        log.trace("offererPaybackAmount=" + offererPaybackAmount.toFriendlyString());
+        log.trace("takerPaybackAmount=" + takerPaybackAmount.toFriendlyString());
         log.trace("offererAddress=" + offererAddress);
         log.trace("callback=" + callback);
 
@@ -1124,24 +1162,25 @@ public class WalletFacade
         }
     }
 
+    //TODO
     private Script getMultiSigScript(String offererPubKey, String takerPubKey, String arbitratorPubKey)
     {
-        ECKey offererKey = new ECKey(null, Utils.parseAsHexOrBase58(offererPubKey));
-        ECKey takerKey = new ECKey(null, Utils.parseAsHexOrBase58(takerPubKey));
-        ECKey arbitratorKey = new ECKey(null, Utils.parseAsHexOrBase58(arbitratorPubKey));
+        ECKey offererKey = wallet.findKeyFromPubKey(Utils.parseAsHexOrBase58(offererPubKey));
+        ECKey takerKey = ECKey.fromPublicOnly(Utils.parseAsHexOrBase58(takerPubKey));
+        ECKey arbitratorKey = ECKey.fromPublicOnly(Utils.parseAsHexOrBase58(arbitratorPubKey));
 
         List<ECKey> keys = ImmutableList.of(offererKey, takerKey, arbitratorKey);
         return ScriptBuilder.createMultiSigOutputScript(2, keys);
     }
 
 
-    private Transaction createPayoutTx(String depositTxAsHex, BigInteger offererPaybackAmount, BigInteger takerPaybackAmount, String offererAddress, String takerAddress) throws AddressFormatException
+    private Transaction createPayoutTx(String depositTxAsHex, Coin offererPaybackAmount, Coin takerPaybackAmount, String offererAddress, String takerAddress) throws AddressFormatException
     {
         log.trace("createPayoutTx");
         log.trace("inputs: ");
         log.trace("depositTxAsHex=" + depositTxAsHex);
-        log.trace("offererPaybackAmount=" + BtcFormatter.formatSatoshis(offererPaybackAmount));
-        log.trace("takerPaybackAmount=" + BtcFormatter.formatSatoshis(takerPaybackAmount));
+        log.trace("offererPaybackAmount=" + offererPaybackAmount.toFriendlyString());
+        log.trace("takerPaybackAmount=" + takerPaybackAmount.toFriendlyString());
         log.trace("offererAddress=" + offererAddress);
         log.trace("takerAddress=" + takerAddress);
 
@@ -1161,7 +1200,7 @@ public class WalletFacade
         {
             if (input.getConnectedOutput() != null)
             {
-                log.trace(tracePrefix + " input value : " + BtcFormatter.formatSatoshis(input.getConnectedOutput().getValue()));
+                log.trace(tracePrefix + " input value : " + input.getConnectedOutput().getValue().toFriendlyString());
             }
             else
             {
@@ -1175,6 +1214,11 @@ public class WalletFacade
     // Inner classes
     ///////////////////////////////////////////////////////////////////////////////////////////
 
+    public static interface StartupListener
+    {
+        void completed();
+    }
+
     public static interface DownloadListener
     {
         void progress(double percent);
diff --git a/src/main/java/io/bitsquare/btc/listeners/BalanceListener.java b/src/main/java/io/bitsquare/btc/listeners/BalanceListener.java
index 6856bfb33c..7ae7153b25 100644
--- a/src/main/java/io/bitsquare/btc/listeners/BalanceListener.java
+++ b/src/main/java/io/bitsquare/btc/listeners/BalanceListener.java
@@ -1,7 +1,7 @@
 package io.bitsquare.btc.listeners;
 
 import com.google.bitcoin.core.Address;
-import java.math.BigInteger;
+import com.google.bitcoin.core.Coin;
 
 public class BalanceListener
 {
@@ -21,7 +21,7 @@ public class BalanceListener
         return address;
     }
 
-    public void onBalanceChanged(BigInteger balance)
+    public void onBalanceChanged(Coin balance)
     {
     }
 }
\ No newline at end of file
diff --git a/src/main/java/io/bitsquare/crypto/CryptoFacade.java b/src/main/java/io/bitsquare/crypto/CryptoFacade.java
index f4bf25a049..082dc82339 100644
--- a/src/main/java/io/bitsquare/crypto/CryptoFacade.java
+++ b/src/main/java/io/bitsquare/crypto/CryptoFacade.java
@@ -49,7 +49,7 @@ public class CryptoFacade
 
     public boolean verifyHash(String hashAsHexStringToVerify, String msg, String sig)
     {
-        String hashAsHexString = Utils.bytesToHexString(createHash(msg, sig));
+        String hashAsHexString = Utils.HEX.encode(createHash(msg, sig));
         return hashAsHexString.equals(hashAsHexStringToVerify);
     }
 
diff --git a/src/main/java/io/bitsquare/di/BitSquareModule.java b/src/main/java/io/bitsquare/di/BitSquareModule.java
index f483256050..3e7017f876 100644
--- a/src/main/java/io/bitsquare/di/BitSquareModule.java
+++ b/src/main/java/io/bitsquare/di/BitSquareModule.java
@@ -9,11 +9,11 @@ import com.google.inject.AbstractModule;
 import com.google.inject.Provider;
 import com.google.inject.name.Named;
 import com.google.inject.name.Names;
-import io.bitsquare.btc.BitSquareWalletAppKit;
 import io.bitsquare.btc.BlockChainFacade;
 import io.bitsquare.btc.FeePolicy;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.crypto.CryptoFacade;
+import io.bitsquare.gui.util.BitSquareFormatter;
 import io.bitsquare.msg.MessageFacade;
 import io.bitsquare.msg.SeedNodeAddress;
 import io.bitsquare.settings.Settings;
@@ -22,7 +22,6 @@ import io.bitsquare.trade.Trading;
 import io.bitsquare.trade.orderbook.OrderBook;
 import io.bitsquare.trade.orderbook.OrderBookFilter;
 import io.bitsquare.user.User;
-import io.bitsquare.util.StorageDirectory;
 import javax.inject.Inject;
 
 public class BitSquareModule extends AbstractModule
@@ -45,6 +44,8 @@ public class BitSquareModule extends AbstractModule
         bind(MessageFacade.class).asEagerSingleton();
 
         bind(Trading.class).asEagerSingleton();
+        bind(BitSquareFormatter.class).asEagerSingleton();
+
 
         //bind(String.class).annotatedWith(Names.named("networkType")).toInstance(WalletFacade.MAIN_NET);
         // how to use reg test see description in the readme file
@@ -52,7 +53,6 @@ public class BitSquareModule extends AbstractModule
         //test net not working yet: http://sourceforge.net/p/bitcoin/mailman/message/32349208/
         //bind(String.class).annotatedWith(Names.named("networkType")).toInstance(WalletFacade.TEST_NET);
         bind(NetworkParameters.class).toProvider(NetworkParametersProvider.class).asEagerSingleton();
-        bind(BitSquareWalletAppKit.class).toProvider(BitSquareWalletAppKitProvider.class).asEagerSingleton();
 
         // bind(Boolean.class).annotatedWith(Names.named("useDiskStorage")).toInstance(new Boolean(true));
         bind(Boolean.class).annotatedWith(Names.named("useDiskStorage")).toInstance(new Boolean(false));
@@ -61,23 +61,6 @@ public class BitSquareModule extends AbstractModule
     }
 }
 
-class BitSquareWalletAppKitProvider implements Provider<BitSquareWalletAppKit>
-{
-    private final NetworkParameters networkParameters;
-
-    @Inject
-    public BitSquareWalletAppKitProvider(NetworkParameters networkParameters)
-    {
-        this.networkParameters = networkParameters;
-    }
-
-
-    public BitSquareWalletAppKit get()
-    {
-        return new BitSquareWalletAppKit(networkParameters, StorageDirectory.getStorageDirectory());
-    }
-}
-
 class NetworkParametersProvider implements Provider<NetworkParameters>
 {
     private final String networkType;
diff --git a/src/main/java/io/bitsquare/gui/MainController.java b/src/main/java/io/bitsquare/gui/MainController.java
index ea72e1a858..05fca21741 100644
--- a/src/main/java/io/bitsquare/gui/MainController.java
+++ b/src/main/java/io/bitsquare/gui/MainController.java
@@ -1,7 +1,7 @@
 package io.bitsquare.gui;
 
+import com.google.bitcoin.core.Coin;
 import io.bitsquare.bank.BankAccount;
-import io.bitsquare.btc.BtcFormatter;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.btc.listeners.BalanceListener;
 import io.bitsquare.di.GuiceFXMLLoader;
@@ -19,7 +19,6 @@ import io.bitsquare.trade.Trading;
 import io.bitsquare.user.User;
 import io.bitsquare.util.AWTSystemTray;
 import java.io.IOException;
-import java.math.BigInteger;
 import java.net.URL;
 import java.util.ResourceBundle;
 import javafx.application.Platform;
@@ -59,6 +58,8 @@ public class MainController implements Initializable, NavigationController
     private Image prevToggleButtonIcon;
     private ToggleButton buyButton, sellButton, homeButton, msgButton, ordersButton, fundsButton, settingsButton;
     private Pane ordersButtonButtonHolder;
+    private boolean messageFacadeInited;
+    private boolean walletFacadeInited;
 
     @FXML
     private Pane contentPane;
@@ -182,21 +183,15 @@ public class MainController implements Initializable, NavigationController
             @Override
             public void onCompleted()
             {
-                messageFacadeInited();
+                messageFacadeInited = true;
+                if (walletFacadeInited) initialisationDone();
             }
 
             @Override
             public void onFailed(Throwable throwable)
             {
-
             }
         });
-    }
-
-    private void messageFacadeInited()
-    {
-
-        trading.addTakeOfferRequestListener(this::onTakeOfferRequested);
 
         walletFacade.addDownloadListener(new WalletFacade.DownloadListener()
         {
@@ -212,9 +207,16 @@ public class MainController implements Initializable, NavigationController
                 networkSyncPane.doneDownload();
             }
         });
+        walletFacade.initialize(() -> {
+            walletFacadeInited = true;
+            if (messageFacadeInited) initialisationDone();
+        });
 
-        walletFacade.initWallet();
+        trading.addTakeOfferRequestListener(this::onTakeOfferRequested);
+    }
 
+    private void initialisationDone()
+    {
         addNavigation();
 
         Transitions.fadeOutAndRemove(loadingLabel);
@@ -320,13 +322,13 @@ public class MainController implements Initializable, NavigationController
         balanceTextField.setEditable(false);
         balanceTextField.setPrefWidth(90);
         balanceTextField.setId("nav-balance-label");
-        balanceTextField.setText(BtcFormatter.formatSatoshis(walletFacade.getWalletBalance()));
+        balanceTextField.setText(walletFacade.getWalletBalance().toFriendlyString());
         walletFacade.addBalanceListener(new BalanceListener()
         {
             @Override
-            public void onBalanceChanged(BigInteger balance)
+            public void onBalanceChanged(Coin balance)
             {
-                balanceTextField.setText(BtcFormatter.formatSatoshis(balance));
+                balanceTextField.setText(balance.toFriendlyString());
             }
         });
 
diff --git a/src/main/java/io/bitsquare/gui/arbitrators/registration/ArbitratorRegistrationController.java b/src/main/java/io/bitsquare/gui/arbitrators/registration/ArbitratorRegistrationController.java
index 26393b8a0f..f80ebc1496 100644
--- a/src/main/java/io/bitsquare/gui/arbitrators/registration/ArbitratorRegistrationController.java
+++ b/src/main/java/io/bitsquare/gui/arbitrators/registration/ArbitratorRegistrationController.java
@@ -1,9 +1,6 @@
 package io.bitsquare.gui.arbitrators.registration;
 
-import com.google.bitcoin.core.ECKey;
-import com.google.bitcoin.core.Transaction;
-import com.google.bitcoin.core.Wallet;
-import com.google.bitcoin.core.WalletEventListener;
+import com.google.bitcoin.core.*;
 import com.google.bitcoin.script.Script;
 import de.jensd.fx.fontawesome.AwesomeDude;
 import de.jensd.fx.fontawesome.AwesomeIcon;
@@ -24,7 +21,6 @@ import io.bitsquare.user.Arbitrator;
 import io.bitsquare.user.Reputation;
 import io.bitsquare.user.User;
 import io.bitsquare.util.DSAKeyUtil;
-import java.math.BigInteger;
 import java.net.URL;
 import java.util.*;
 import javafx.collections.FXCollections;
@@ -376,44 +372,50 @@ public class ArbitratorRegistrationController implements Initializable, ChildCon
         });
 
         confidenceDisplay = new ConfidenceDisplay(walletFacade.getWallet(), confirmationLabel, balanceTextField, progressIndicator);
-        paymentDoneButton.setDisable(walletFacade.getArbitratorDepositBalance().compareTo(BigInteger.ZERO) == 0);
+        paymentDoneButton.setDisable(walletFacade.getArbitratorDepositBalance().isZero());
         log.debug("getArbitratorDepositBalance " + walletFacade.getArbitratorDepositBalance());
         walletFacade.getWallet().addEventListener(new WalletEventListener()
         {
             @Override
-            public void onCoinsReceived(Wallet wallet, Transaction tx, BigInteger prevBalance, BigInteger newBalance)
+            public void onCoinsReceived(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance)
             {
-                paymentDoneButton.setDisable(newBalance.compareTo(BigInteger.ZERO) == 0);
+                paymentDoneButton.setDisable(newBalance.isZero());
             }
 
             @Override
-            public void onTransactionConfidenceChanged(Wallet wallet, Transaction tx)
+            public void onCoinsSent(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance)
             {
-            }
 
-            @Override
-            public void onCoinsSent(Wallet wallet, Transaction tx, BigInteger prevBalance, BigInteger newBalance)
-            {
             }
 
             @Override
             public void onReorganize(Wallet wallet)
             {
+
+            }
+
+            @Override
+            public void onTransactionConfidenceChanged(Wallet wallet, Transaction tx)
+            {
+
             }
 
             @Override
             public void onWalletChanged(Wallet wallet)
             {
-            }
 
-            @Override
-            public void onKeysAdded(Wallet wallet, List<ECKey> keys)
-            {
             }
 
             @Override
             public void onScriptsAdded(Wallet wallet, List<Script> scripts)
             {
+
+            }
+
+            @Override
+            public void onKeysAdded(List<ECKey> keys)
+            {
+
             }
         });
     }
diff --git a/src/main/java/io/bitsquare/gui/components/btc/BalanceTextField.java b/src/main/java/io/bitsquare/gui/components/btc/BalanceTextField.java
index e4ffd20cb8..e8c58a5643 100644
--- a/src/main/java/io/bitsquare/gui/components/btc/BalanceTextField.java
+++ b/src/main/java/io/bitsquare/gui/components/btc/BalanceTextField.java
@@ -1,13 +1,12 @@
 package io.bitsquare.gui.components.btc;
 
 import com.google.bitcoin.core.Address;
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.TransactionConfidence;
-import io.bitsquare.btc.BtcFormatter;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.btc.listeners.BalanceListener;
 import io.bitsquare.btc.listeners.ConfidenceListener;
 import io.bitsquare.gui.components.confidence.ConfidenceProgressIndicator;
-import java.math.BigInteger;
 import javafx.scene.control.TextField;
 import javafx.scene.control.Tooltip;
 import javafx.scene.layout.AnchorPane;
@@ -80,7 +79,7 @@ public class BalanceTextField extends AnchorPane
         balanceListener = walletFacade.addBalanceListener(new BalanceListener(address)
         {
             @Override
-            public void onBalanceChanged(BigInteger balance)
+            public void onBalanceChanged(Coin balance)
             {
                 updateBalance(balance);
             }
@@ -133,11 +132,12 @@ public class BalanceTextField extends AnchorPane
         }
     }
 
-    private void updateBalance(BigInteger balance)
+    private void updateBalance(Coin balance)
     {
         if (balance != null)
         {
-            balanceTextField.setText(BtcFormatter.formatSatoshis(balance));
+            //TODO use BitSquareFormatter
+            balanceTextField.setText(balance.toFriendlyString());
         }
     }
 }
diff --git a/src/main/java/io/bitsquare/gui/funds/transactions/TransactionsListItem.java b/src/main/java/io/bitsquare/gui/funds/transactions/TransactionsListItem.java
index a3557e3e66..c73653ab41 100644
--- a/src/main/java/io/bitsquare/gui/funds/transactions/TransactionsListItem.java
+++ b/src/main/java/io/bitsquare/gui/funds/transactions/TransactionsListItem.java
@@ -1,15 +1,10 @@
 package io.bitsquare.gui.funds.transactions;
 
-import com.google.bitcoin.core.Address;
-import com.google.bitcoin.core.Transaction;
-import com.google.bitcoin.core.TransactionConfidence;
-import com.google.bitcoin.core.TransactionOutput;
-import io.bitsquare.btc.BtcFormatter;
+import com.google.bitcoin.core.*;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.btc.listeners.ConfidenceListener;
 import io.bitsquare.gui.components.confidence.ConfidenceProgressIndicator;
 import io.bitsquare.gui.util.BitSquareFormatter;
-import java.math.BigInteger;
 import javafx.beans.property.SimpleStringProperty;
 import javafx.beans.property.StringProperty;
 import javafx.scene.control.Tooltip;
@@ -35,12 +30,13 @@ public class TransactionsListItem
     {
         this.walletFacade = walletFacade;
 
-        BigInteger valueSentToMe = transaction.getValueSentToMe(walletFacade.getWallet());
-        BigInteger valueSentFromMe = transaction.getValueSentFromMe(walletFacade.getWallet());
+        Coin valueSentToMe = transaction.getValueSentToMe(walletFacade.getWallet());
+        Coin valueSentFromMe = transaction.getValueSentFromMe(walletFacade.getWallet());
         Address address = null;
-        if (valueSentToMe.compareTo(BigInteger.ZERO) == 0)
+        if (valueSentToMe.isZero())
         {
-            amount.set("-" + BtcFormatter.formatSatoshis(valueSentFromMe));
+            //TODO use BitSquareFormatter
+            amount.set("-" + valueSentFromMe.toFriendlyString());
 
             for (TransactionOutput transactionOutput : transaction.getOutputs())
             {
@@ -48,7 +44,7 @@ public class TransactionsListItem
                 {
                     type.set("Sent to");
 
-                    if (transactionOutput.getScriptPubKey().isSentToAddress() || transactionOutput.getScriptPubKey().isSentToP2SH())
+                    if (transactionOutput.getScriptPubKey().isSentToAddress() || transactionOutput.getScriptPubKey().isPayToScriptHash())
                     {
                         address = transactionOutput.getScriptPubKey().getToAddress(walletFacade.getWallet().getParams());
                         addressString = address.toString();
@@ -60,16 +56,17 @@ public class TransactionsListItem
                 }
             }
         }
-        else if (valueSentFromMe.compareTo(BigInteger.ZERO) == 0)
+        else if (valueSentFromMe.isZero())
         {
-            amount.set(BtcFormatter.formatSatoshis(valueSentToMe));
+            //TODO use BitSquareFormatter
+            amount.set(valueSentToMe.toFriendlyString());
             type.set("Received with");
 
             for (TransactionOutput transactionOutput : transaction.getOutputs())
             {
                 if (transactionOutput.isMine(walletFacade.getWallet()))
                 {
-                    if (transactionOutput.getScriptPubKey().isSentToAddress() || transactionOutput.getScriptPubKey().isSentToP2SH())
+                    if (transactionOutput.getScriptPubKey().isSentToAddress() || transactionOutput.getScriptPubKey().isPayToScriptHash())
                     {
                         address = transactionOutput.getScriptPubKey().getToAddress(walletFacade.getWallet().getParams());
                         addressString = address.toString();
@@ -83,7 +80,8 @@ public class TransactionsListItem
         }
         else
         {
-            amount.set(BtcFormatter.formatSatoshis(valueSentToMe.subtract(valueSentFromMe)));
+            //TODO use BitSquareFormatter
+            amount.set(valueSentToMe.subtract(valueSentFromMe).toFriendlyString());
 
             boolean outgoing = false;
             for (TransactionOutput transactionOutput : transaction.getOutputs())
@@ -91,7 +89,7 @@ public class TransactionsListItem
                 if (!transactionOutput.isMine(walletFacade.getWallet()))
                 {
                     outgoing = true;
-                    if (transactionOutput.getScriptPubKey().isSentToAddress() || transactionOutput.getScriptPubKey().isSentToP2SH())
+                    if (transactionOutput.getScriptPubKey().isSentToAddress() || transactionOutput.getScriptPubKey().isPayToScriptHash())
                     {
                         address = transactionOutput.getScriptPubKey().getToAddress(walletFacade.getWallet().getParams());
                         addressString = address.toString();
diff --git a/src/main/java/io/bitsquare/gui/funds/withdrawal/WithdrawalController.java b/src/main/java/io/bitsquare/gui/funds/withdrawal/WithdrawalController.java
index 41b6ed2703..0411f73002 100644
--- a/src/main/java/io/bitsquare/gui/funds/withdrawal/WithdrawalController.java
+++ b/src/main/java/io/bitsquare/gui/funds/withdrawal/WithdrawalController.java
@@ -1,18 +1,22 @@
 package io.bitsquare.gui.funds.withdrawal;
 
 import com.google.bitcoin.core.AddressFormatException;
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.InsufficientMoneyException;
 import com.google.bitcoin.core.Transaction;
 import com.google.common.util.concurrent.FutureCallback;
 import de.jensd.fx.fontawesome.AwesomeDude;
 import de.jensd.fx.fontawesome.AwesomeIcon;
-import io.bitsquare.btc.*;
+import io.bitsquare.btc.AddressEntry;
+import io.bitsquare.btc.BtcValidator;
+import io.bitsquare.btc.FeePolicy;
+import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.gui.ChildController;
 import io.bitsquare.gui.Hibernate;
 import io.bitsquare.gui.NavigationController;
 import io.bitsquare.gui.popups.Popups;
+import io.bitsquare.gui.util.BitSquareFormatter;
 import io.bitsquare.gui.util.BitSquareValidator;
-import java.math.BigInteger;
 import java.net.URL;
 import java.util.List;
 import java.util.ResourceBundle;
@@ -81,9 +85,9 @@ public class WithdrawalController implements Initializable, ChildController, Hib
             {
                 BitSquareValidator.resetTextFields(withdrawFromTextField, withdrawToTextField, amountTextField, changeAddressTextField);
 
-                if (BigInteger.ZERO.compareTo(newValue.getBalance()) <= 0)
+                if (Coin.ZERO.compareTo(newValue.getBalance()) <= 0)
                 {
-                    amountTextField.setText(BtcFormatter.formatSatoshis(newValue.getBalance()));
+                    amountTextField.setText(newValue.getBalance().toPlainString());
                     withdrawFromTextField.setText(newValue.getAddressEntry().getAddressString());
                     changeAddressTextField.setText(newValue.getAddressEntry().getAddressString());
                 }
@@ -151,7 +155,7 @@ public class WithdrawalController implements Initializable, ChildController, Hib
             BitSquareValidator.textFieldsNotEmpty(amountTextField, withdrawFromTextField, withdrawToTextField, changeAddressTextField);
             BitSquareValidator.textFieldsHasDoubleValueWithReset(amountTextField);
 
-            BigInteger amount = BtcFormatter.stringValueToSatoshis(amountTextField.getText());
+            Coin amount = BitSquareFormatter.parseBtcToCoin(amountTextField.getText());
             if (BtcValidator.isMinSpendableAmount(amount))
             {
                 FutureCallback<Transaction> callback = new FutureCallback<Transaction>()
@@ -177,8 +181,8 @@ public class WithdrawalController implements Initializable, ChildController, Hib
                         "Amount: " + amountTextField.getText() + " BTC\n" +
                         "Sending address: " + withdrawFromTextField.getText() + "\n" +
                         "Receiving address: " + withdrawToTextField.getText() + "\n" +
-                        "Transaction fee: " + BtcFormatter.formatSatoshis(FeePolicy.TX_FEE) + "\n" +
-                        "You receive in total: " + BtcFormatter.formatSatoshis(amount.subtract(FeePolicy.TX_FEE)) + " BTC\n\n" +
+                        "Transaction fee: " + BitSquareFormatter.formatCoinToBtcWithCode(FeePolicy.TX_FEE) + "\n" +
+                        "You receive in total: " + BitSquareFormatter.formatCoinToBtcWithCode(amount.subtract(FeePolicy.TX_FEE)) + " BTC\n\n" +
                         "Are you sure you withdraw that amount?");
                 if (response == Dialog.Actions.OK)
                 {
diff --git a/src/main/java/io/bitsquare/gui/funds/withdrawal/WithdrawalListItem.java b/src/main/java/io/bitsquare/gui/funds/withdrawal/WithdrawalListItem.java
index 05ff1aa395..0d2236d5cc 100644
--- a/src/main/java/io/bitsquare/gui/funds/withdrawal/WithdrawalListItem.java
+++ b/src/main/java/io/bitsquare/gui/funds/withdrawal/WithdrawalListItem.java
@@ -1,14 +1,13 @@
 package io.bitsquare.gui.funds.withdrawal;
 
 import com.google.bitcoin.core.Address;
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.TransactionConfidence;
 import io.bitsquare.btc.AddressEntry;
-import io.bitsquare.btc.BtcFormatter;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.btc.listeners.BalanceListener;
 import io.bitsquare.btc.listeners.ConfidenceListener;
 import io.bitsquare.gui.components.confidence.ConfidenceProgressIndicator;
-import java.math.BigInteger;
 import javafx.beans.property.SimpleStringProperty;
 import javafx.beans.property.StringProperty;
 import javafx.scene.control.Label;
@@ -30,7 +29,7 @@ public class WithdrawalListItem
 
     private final Tooltip tooltip;
 
-    private BigInteger balance;
+    private Coin balance;
 
     public WithdrawalListItem(AddressEntry addressEntry, WalletFacade walletFacade)
     {
@@ -63,7 +62,7 @@ public class WithdrawalListItem
         balanceListener = walletFacade.addBalanceListener(new BalanceListener(getAddress())
         {
             @Override
-            public void onBalanceChanged(BigInteger balance)
+            public void onBalanceChanged(Coin balance)
             {
                 updateBalance(balance);
             }
@@ -78,12 +77,13 @@ public class WithdrawalListItem
         walletFacade.removeBalanceListener(balanceListener);
     }
 
-    private void updateBalance(BigInteger balance)
+    private void updateBalance(Coin balance)
     {
         this.balance = balance;
         if (balance != null)
         {
-            balanceLabel.setText(BtcFormatter.formatSatoshis(balance));
+            //TODO use BitSquareFormatter
+            balanceLabel.setText(balance.toFriendlyString());
         }
     }
 
@@ -166,7 +166,7 @@ public class WithdrawalListItem
     }
 
 
-    public BigInteger getBalance()
+    public Coin getBalance()
     {
         return balance;
     }
diff --git a/src/main/java/io/bitsquare/gui/market/createOffer/CreateOfferController.java b/src/main/java/io/bitsquare/gui/market/createOffer/CreateOfferController.java
index efb401a1cb..479017c4c3 100644
--- a/src/main/java/io/bitsquare/gui/market/createOffer/CreateOfferController.java
+++ b/src/main/java/io/bitsquare/gui/market/createOffer/CreateOfferController.java
@@ -1,12 +1,12 @@
 package io.bitsquare.gui.market.createOffer;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.InsufficientMoneyException;
 import com.google.bitcoin.core.Transaction;
 import com.google.common.util.concurrent.FutureCallback;
 import io.bitsquare.BitSquare;
 import io.bitsquare.bank.BankAccount;
 import io.bitsquare.btc.AddressEntry;
-import io.bitsquare.btc.BtcFormatter;
 import io.bitsquare.btc.FeePolicy;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.gui.ChildController;
@@ -19,6 +19,7 @@ import io.bitsquare.gui.components.confidence.ConfidenceProgressIndicator;
 import io.bitsquare.gui.popups.Popups;
 import io.bitsquare.gui.util.BitSquareConverter;
 import io.bitsquare.gui.util.BitSquareFormatter;
+import io.bitsquare.gui.util.BitSquareValidator;
 import io.bitsquare.locale.Localisation;
 import io.bitsquare.settings.Settings;
 import io.bitsquare.trade.Direction;
@@ -28,7 +29,6 @@ import io.bitsquare.trade.orderbook.OrderBookFilter;
 import io.bitsquare.user.Arbitrator;
 import io.bitsquare.user.User;
 import java.io.IOException;
-import java.math.BigInteger;
 import java.net.URL;
 import java.util.Random;
 import java.util.ResourceBundle;
@@ -53,6 +53,7 @@ public class CreateOfferController implements Initializable, ChildController, Hi
     private final Settings settings;
     private final User user;
 
+
     private NavigationController navigationController;
     private Direction direction;
     private Offer offer;
@@ -61,7 +62,7 @@ public class CreateOfferController implements Initializable, ChildController, Hi
     @FXML
     private AnchorPane rootContainer;
     @FXML
-    private Label buyLabel, placeOfferTitle, confirmationLabel, txTitleLabel;
+    private Label buyLabel, placeOfferTitle, confirmationLabel, txTitleLabel, collateralLabel;
     @FXML
     private TextField volumeTextField, amountTextField, priceTextField, totalTextField;
     @FXML
@@ -85,6 +86,7 @@ public class CreateOfferController implements Initializable, ChildController, Hi
         this.walletFacade = walletFacade;
         this.settings = settings;
         this.user = user;
+
     }
 
 
@@ -95,11 +97,15 @@ public class CreateOfferController implements Initializable, ChildController, Hi
     public void setOrderBookFilter(OrderBookFilter orderBookFilter)
     {
         direction = orderBookFilter.getDirection();
+        //TODO
         amountTextField.setText(BitSquareFormatter.formatPrice(orderBookFilter.getAmount()));
+        //TODO
         minAmountTextField.setText(BitSquareFormatter.formatPrice(orderBookFilter.getAmount()));
+
         priceTextField.setText(BitSquareFormatter.formatPrice(orderBookFilter.getPrice()));
         buyLabel.setText(BitSquareFormatter.formatDirection(direction, false) + ":");
-        collateralTextField.setText(BitSquareFormatter.formatVolume(settings.getMinCollateral()));
+        collateralLabel.setText("Collateral (" + getCollateralAsPercent() + "):");
+
         updateVolume();
         updateTotals();
 
@@ -109,18 +115,17 @@ public class CreateOfferController implements Initializable, ChildController, Hi
             //amountTextField.setText("" + (int) (new Random().nextDouble() * 100 / 10 + 1));
             amountTextField.setText("1");
             priceTextField.setText("" + (int) (499 - new Random().nextDouble() * 1000 / 100));
-            minAmountTextField.setText("0,1");
+            minAmountTextField.setText("0.1");
         }
 
-        //TODO derive form arbitrators
-        collateralTextField.setText("10");
-
         updateVolume();
         updateTotals();
+        applyCollateral();
 
         amountTextField.textProperty().addListener((observable, oldValue, newValue) -> {
             updateVolume();
             updateTotals();
+            applyCollateral();
         });
 
         priceTextField.textProperty().addListener((observable, oldValue, newValue) -> updateVolume());
@@ -143,7 +148,7 @@ public class CreateOfferController implements Initializable, ChildController, Hi
         }
         acceptedCountriesTextField.setText(BitSquareFormatter.countryLocalesToString(settings.getAcceptedCountries()));
         acceptedLanguagesTextField.setText(BitSquareFormatter.languageLocalesToString(settings.getAcceptedLanguageLocales()));
-        feeLabel.setText(BtcFormatter.formatSatoshis(FeePolicy.CREATE_OFFER_FEE));
+        feeLabel.setText(BitSquareFormatter.formatCoinToBtcWithCode(FeePolicy.CREATE_OFFER_FEE.add(FeePolicy.TX_FEE)));
 
         addressEntry = walletFacade.getUnusedTradeAddressInfo();
         addressTextField.setAddress(addressEntry.getAddress().toString());
@@ -197,8 +202,9 @@ public class CreateOfferController implements Initializable, ChildController, Hi
             return;
         }
 
-        int collateral = (int) (BitSquareConverter.stringToDouble(collateralTextField.getText()));
-        Arbitrator arbitrator = settings.getRandomArbitrator(collateral, getAmountAsBI());
+        //TODO will be derived form arbitrators
+        double collateral = getCollateral();
+        Arbitrator arbitrator = settings.getRandomArbitrator(collateral, getAmountAsCoin());
         if (arbitrator == null)
         {
             Popups.openWarningPopup("No arbitrator available", "No arbitrator from your arbitrator list does match the collateral and amount value.");
@@ -207,11 +213,14 @@ public class CreateOfferController implements Initializable, ChildController, Hi
 
         if (user.getCurrentBankAccount() != null)
         {
+            Coin amountAsCoin = BitSquareFormatter.parseBtcToCoin(getAmountString());
+            Coin minAmountAsCoin = BitSquareFormatter.parseBtcToCoin(getAmountString());
+
             offer = new Offer(user.getMessagePublicKey(),
                               direction,
                               BitSquareConverter.stringToDouble(priceTextField.getText()),
-                              BtcFormatter.stringValueToSatoshis(amountTextField.getText()),
-                              BtcFormatter.stringValueToSatoshis(minAmountTextField.getText()),
+                              amountAsCoin,
+                              minAmountAsCoin,
                               user.getCurrentBankAccount().getBankAccountType(),
                               user.getCurrentBankAccount().getCurrency(),
                               user.getCurrentBankAccount().getCountry(),
@@ -292,12 +301,10 @@ public class CreateOfferController implements Initializable, ChildController, Hi
 
     private void updateTotals()
     {
-        double amountAsDouble = BitSquareConverter.stringToDouble(amountTextField.getText());
-        double collateralPercentAsDouble = BitSquareConverter.stringToDouble(collateralTextField.getText());
-        double collateralAmountAsDouble = collateralPercentAsDouble * amountAsDouble / 100;
-        BigInteger collateral = BtcFormatter.doubleValueToSatoshis(collateralAmountAsDouble);
-        BigInteger totals = FeePolicy.CREATE_OFFER_FEE.add(collateral).add(FeePolicy.TX_FEE);
-        totalTextField.setText(BtcFormatter.formatSatoshis(totals));
+        Coin amountAsCoin = BitSquareFormatter.parseBtcToCoin(getAmountString());
+        Coin collateral = amountAsCoin.divide((long) (1d / getCollateral()));
+        Coin totals = FeePolicy.CREATE_OFFER_FEE.add(collateral).add(FeePolicy.TX_FEE);
+        totalTextField.setText(BitSquareFormatter.formatCoinToBtcWithCode(totals));
     }
 
     private void updateVolume()
@@ -307,23 +314,57 @@ public class CreateOfferController implements Initializable, ChildController, Hi
 
     private double getVolume()
     {
-        double amountAsDouble = BitSquareConverter.stringToDouble(amountTextField.getText());
+        double amountAsDouble = BitSquareConverter.stringToDouble(getAmountString());
         double priceAsDouble = BitSquareConverter.stringToDouble(priceTextField.getText());
         return amountAsDouble * priceAsDouble;
     }
 
-    private BigInteger getAmountAsBI()
+    private void applyCollateral()
     {
-        return BtcFormatter.stringValueToSatoshis(amountTextField.getText());
+        collateralTextField.setText(getFormattedCollateralAsBtc());
+    }
+
+    private String getFormattedCollateralAsBtc()
+    {
+        Coin amountAsCoin = BitSquareFormatter.parseBtcToCoin(getAmountString());
+        Coin collateralAsCoin = amountAsCoin.divide((long) (1d / getCollateral()));
+        return BitSquareFormatter.formatCoinToBtc(collateralAsCoin);
+    }
+
+    private String getCollateralAsPercent()
+    {
+        return BitSquareFormatter.formatCollateralPercent(getCollateral());
+    }
+
+
+    private Coin getAmountAsCoin()
+    {
+        return BitSquareFormatter.parseBtcToCoin(getAmountString());
+    }
+
+    private String getAmountString()
+    {
+        try
+        {
+            BitSquareValidator.textFieldsHasPositiveDoubleValueWithReset(amountTextField);
+            return amountTextField.getText();
+        } catch (BitSquareValidator.ValidationException e)
+        {
+            return "0";
+        }
+    }
+
+    private double getCollateral()
+    {
+        // TODO
+        return settings.getCollateral();
     }
 
-    //TODO
-    @SuppressWarnings("UnusedAssignment")
     private boolean inputValid()
     {
         double priceAsDouble = BitSquareConverter.stringToDouble(priceTextField.getText());
         double minAmountAsDouble = BitSquareConverter.stringToDouble(minAmountTextField.getText());
-        double amountAsDouble = BitSquareConverter.stringToDouble(amountTextField.getText());
+        double amountAsDouble = BitSquareConverter.stringToDouble(getAmountString());
         double collateralAsDouble = BitSquareConverter.stringToDouble(collateralTextField.getText());
 
         return priceAsDouble > 0 &&
diff --git a/src/main/java/io/bitsquare/gui/market/createOffer/CreateOfferView.fxml b/src/main/java/io/bitsquare/gui/market/createOffer/CreateOfferView.fxml
index a408b77706..7bb299d324 100644
--- a/src/main/java/io/bitsquare/gui/market/createOffer/CreateOfferView.fxml
+++ b/src/main/java/io/bitsquare/gui/market/createOffer/CreateOfferView.fxml
@@ -27,19 +27,19 @@
         <Label text="Min. Amount:" GridPane.rowIndex="2"/>
         <TextField fx:id="minAmountTextField" GridPane.columnIndex="1" GridPane.rowIndex="2"/>
 
-        <Label text="Collateral (%):" GridPane.rowIndex="3"/>
+        <Label fx:id="collateralLabel" text="Collateral:" GridPane.rowIndex="3"/>
         <TextField fx:id="collateralTextField" editable="false" GridPane.columnIndex="1" GridPane.rowIndex="3"/>
 
-        <Label text="Offer fee:" GridPane.rowIndex="4"/>
+        <Label text="Total Fees (Offer + tx)" GridPane.rowIndex="4"/>
         <TextField fx:id="feeLabel" editable="false" GridPane.columnIndex="1" GridPane.rowIndex="4"/>
 
-        <Label text="Total BTC funds needed:" GridPane.rowIndex="5"/>
+        <Label text="Total funds needed:" GridPane.rowIndex="5"/>
         <TextField fx:id="totalTextField" editable="false" GridPane.columnIndex="1" GridPane.rowIndex="5"/>
 
         <Label text="BTC address for deposit:" GridPane.rowIndex="6"/>
         <AddressTextField fx:id="addressTextField" GridPane.columnIndex="1" GridPane.rowIndex="6"/>
 
-        <Label text="Balance:" GridPane.rowIndex="7"/>
+        <Label text="Actual balance:" GridPane.rowIndex="7"/>
         <BalanceTextField fx:id="balanceTextField" GridPane.columnIndex="1" GridPane.rowIndex="7"/>
 
         <!--
diff --git a/src/main/java/io/bitsquare/gui/market/orderbook/OrderBookController.java b/src/main/java/io/bitsquare/gui/market/orderbook/OrderBookController.java
index 1cdf31d261..bb25c6e2e1 100644
--- a/src/main/java/io/bitsquare/gui/market/orderbook/OrderBookController.java
+++ b/src/main/java/io/bitsquare/gui/market/orderbook/OrderBookController.java
@@ -1,10 +1,10 @@
 package io.bitsquare.gui.market.orderbook;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.InsufficientMoneyException;
 import com.google.bitcoin.core.Transaction;
 import com.google.common.util.concurrent.FutureCallback;
 import io.bitsquare.bank.BankAccountType;
-import io.bitsquare.btc.BtcFormatter;
 import io.bitsquare.btc.FeePolicy;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.gui.ChildController;
@@ -29,7 +29,6 @@ import io.bitsquare.trade.orderbook.OrderBook;
 import io.bitsquare.trade.orderbook.OrderBookFilter;
 import io.bitsquare.user.User;
 import io.bitsquare.util.Utilities;
-import java.math.BigInteger;
 import java.net.URL;
 import java.text.DecimalFormat;
 import java.text.ParseException;
@@ -66,6 +65,7 @@ public class OrderBookController implements Initializable, ChildController
     private final WalletFacade walletFacade;
     private final Settings settings;
     private final Persistence persistence;
+
     private final Image buyIcon = Icons.getIconImage(Icons.BUY);
     private final Image sellIcon = Icons.getIconImage(Icons.SELL);
     @FXML
@@ -230,7 +230,7 @@ public class OrderBookController implements Initializable, ChildController
                 else
                 {
                     Action response = Popups.openErrorPopup("Missing registration fee",
-                                                            "You have not funded the full registration fee of " + BtcFormatter.formatSatoshis(FeePolicy.ACCOUNT_REGISTRATION_FEE) + " BTC.");
+                                                            "You have not funded the full registration fee of " + BitSquareFormatter.formatCoinToBtcWithCode(FeePolicy.ACCOUNT_REGISTRATION_FEE) + " BTC.");
                     if (response == Dialog.Actions.OK)
                     {
                         MainController.GET_INSTANCE().navigateToView(NavigationItem.FUNDS);
@@ -341,10 +341,10 @@ public class OrderBookController implements Initializable, ChildController
         {
             TakerOfferController takerOfferController = (TakerOfferController) navigationController.navigateToView(NavigationItem.TAKE_OFFER);
 
-            BigInteger requestedAmount;
+            Coin requestedAmount;
             if (!"".equals(amount.getText()))
             {
-                requestedAmount = BtcFormatter.stringValueToSatoshis(amount.getText());
+                requestedAmount = BitSquareFormatter.parseBtcToCoin(amount.getText());
             }
             else
             {
diff --git a/src/main/java/io/bitsquare/gui/market/orderbook/OrderBookListItem.java b/src/main/java/io/bitsquare/gui/market/orderbook/OrderBookListItem.java
index 7ba89dac2e..0f4354b037 100644
--- a/src/main/java/io/bitsquare/gui/market/orderbook/OrderBookListItem.java
+++ b/src/main/java/io/bitsquare/gui/market/orderbook/OrderBookListItem.java
@@ -1,6 +1,5 @@
 package io.bitsquare.gui.market.orderbook;
 
-import io.bitsquare.btc.BtcFormatter;
 import io.bitsquare.gui.util.BitSquareFormatter;
 import io.bitsquare.trade.Offer;
 import javafx.beans.property.SimpleStringProperty;
@@ -20,11 +19,7 @@ public class OrderBookListItem
     {
         this.offer = offer;
         this.price.set(BitSquareFormatter.formatPrice(offer.getPrice()));
-
-        double amountAsBtcDouble = BtcFormatter.satoshiToBTC(offer.getAmount());
-        double minAmountAsBtcDouble = BtcFormatter.satoshiToBTC(offer.getMinAmount());
-        this.amount.set(BitSquareFormatter.formatAmountWithMinAmount(amountAsBtcDouble, minAmountAsBtcDouble));
-
+        this.amount.set(BitSquareFormatter.formatCoinToBtc(offer.getAmount()) + " (" + BitSquareFormatter.formatCoinToBtc(offer.getMinAmount()) + ")");
         this.volume.set(BitSquareFormatter.formatVolumeWithMinVolume(offer.getVolume(), offer.getMinVolume()));
     }
 
diff --git a/src/main/java/io/bitsquare/gui/market/trade/TakeOfferView.fxml b/src/main/java/io/bitsquare/gui/market/trade/TakeOfferView.fxml
index 1e64f1eafd..4f5c17dd21 100644
--- a/src/main/java/io/bitsquare/gui/market/trade/TakeOfferView.fxml
+++ b/src/main/java/io/bitsquare/gui/market/trade/TakeOfferView.fxml
@@ -27,13 +27,13 @@
                         <Label text="Volume (EUR):" GridPane.rowIndex="3"/>
                         <TextField fx:id="volumeTextField" editable="false" GridPane.rowIndex="3" GridPane.columnIndex="1"/>
 
-                        <Label text="Collateral (BTC):" GridPane.rowIndex="4"/>
+                        <Label fx:id="collateralLabel" text="Collateral:" GridPane.rowIndex="4"/>
                         <TextField fx:id="collateralTextField" editable="false" GridPane.rowIndex="4" GridPane.columnIndex="1"/>
 
-                        <Label text="Fee (BTC):" GridPane.rowIndex="5"/>
+                        <Label text="Total Fees (Offer + tx):" GridPane.rowIndex="5"/>
                         <TextField fx:id="feeTextField" editable="false" GridPane.rowIndex="5" GridPane.columnIndex="1"/>
 
-                        <Label text="Total (BTC):" GridPane.rowIndex="6"/>
+                        <Label text="Total:" GridPane.rowIndex="6"/>
                         <TextField fx:id="totalTextField" editable="false" GridPane.rowIndex="6" GridPane.columnIndex="1"/>
 
                         <Button fx:id="takeOfferButton" text="Take offer and pay" onAction="#onTakeOffer" defaultButton="true" GridPane.rowIndex="7" GridPane.columnIndex="1"/>
diff --git a/src/main/java/io/bitsquare/gui/market/trade/TakerOfferController.java b/src/main/java/io/bitsquare/gui/market/trade/TakerOfferController.java
index 9911690fec..595d658ac4 100644
--- a/src/main/java/io/bitsquare/gui/market/trade/TakerOfferController.java
+++ b/src/main/java/io/bitsquare/gui/market/trade/TakerOfferController.java
@@ -1,7 +1,7 @@
 package io.bitsquare.gui.market.trade;
 
+import com.google.bitcoin.core.Coin;
 import io.bitsquare.btc.AddressEntry;
-import io.bitsquare.btc.BtcFormatter;
 import io.bitsquare.btc.FeePolicy;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.gui.ChildController;
@@ -18,7 +18,6 @@ import io.bitsquare.trade.Trade;
 import io.bitsquare.trade.Trading;
 import io.bitsquare.trade.protocol.taker.ProtocolForTakerAsSeller;
 import io.bitsquare.trade.protocol.taker.ProtocolForTakerAsSellerListener;
-import java.math.BigInteger;
 import java.net.URL;
 import java.util.ResourceBundle;
 import javafx.fxml.FXML;
@@ -38,9 +37,10 @@ public class TakerOfferController implements Initializable, ChildController
     private final WalletFacade walletFacade;
     private final MessageFacade messageFacade;
 
+
     private NavigationController navigationController;
     private Offer offer;
-    private BigInteger requestedAmount;
+    private Coin requestedAmount;
     private String tradeId;
     private String depositTxId;
 
@@ -57,7 +57,7 @@ public class TakerOfferController implements Initializable, ChildController
             supportedLanguagesTextField, supportedCountriesTextField, depositTxIdTextField, summaryPaidTextField, summaryReceivedTextField, summaryFeesTextField, summaryCollateralTextField,
             summaryDepositTxIdTextField, summaryPayoutTxIdTextField;
     @FXML
-    private Label infoLabel, headLineLabel;
+    private Label infoLabel, headLineLabel, collateralLabel;
     @FXML
     private Button takeOfferButton, receivedFiatButton;
 
@@ -78,10 +78,10 @@ public class TakerOfferController implements Initializable, ChildController
     // Public methods
     ///////////////////////////////////////////////////////////////////////////////////////////
 
-    public void initWithData(Offer offer, BigInteger requestedAmount)
+    public void initWithData(Offer offer, Coin requestedAmount)
     {
         this.offer = offer;
-        this.requestedAmount = requestedAmount.compareTo(BigInteger.ZERO) == 0 ? offer.getAmount() : requestedAmount;
+        this.requestedAmount = requestedAmount.compareTo(Coin.ZERO) == 0 ? offer.getAmount() : requestedAmount;
 
         if (amountTextField != null)
         {
@@ -101,13 +101,14 @@ public class TakerOfferController implements Initializable, ChildController
 
     public void applyData()
     {
-        amountTextField.setText(BtcFormatter.formatSatoshis(requestedAmount));
-        amountTextField.setPromptText(BtcFormatter.formatSatoshis(offer.getMinAmount()) + " - " + BtcFormatter.formatSatoshis(offer.getAmount()));
+        amountTextField.setText(requestedAmount.toPlainString());
+        amountTextField.setPromptText(BitSquareFormatter.formatCoinToBtcWithCode(offer.getMinAmount()) + " - " + BitSquareFormatter.formatCoinToBtcWithCode(offer.getAmount()));
         priceTextField.setText(BitSquareFormatter.formatPrice(offer.getPrice()));
         applyVolume();
+        collateralLabel.setText("Collateral (" + getCollateralAsPercent() + "):");
         applyCollateral();
         applyTotal();
-        feeTextField.setText(BtcFormatter.formatSatoshis(getFee()));
+        feeTextField.setText(BitSquareFormatter.formatCoinToBtcWithCode(getFee()));
         totalTextField.setText(getFormattedTotal());
 
         bankAccountTypeTextField.setText(offer.getBankAccountType().toString());
@@ -123,7 +124,6 @@ public class TakerOfferController implements Initializable, ChildController
             applyVolume();
             applyCollateral();
             applyTotal();
-
         });
     }
 
@@ -152,7 +152,7 @@ public class TakerOfferController implements Initializable, ChildController
     public void onTakeOffer()
     {
         AddressEntry addressEntry = walletFacade.getAddressInfoByTradeID(offer.getId());
-        BigInteger amount = BtcFormatter.stringValueToSatoshis(amountTextField.getText());
+        Coin amount = BitSquareFormatter.parseBtcToCoin(getAmountString());
         // TODO more validation (fee payment, blacklist,...)
         if (amountTextField.isInvalid())
         {
@@ -200,10 +200,10 @@ public class TakerOfferController implements Initializable, ChildController
                 public void onPayoutTxPublished(Trade trade, String payoutTxId)
                 {
                     accordion.setExpandedPane(summaryTitledPane);
-                    summaryPaidTextField.setText(BtcFormatter.formatSatoshis(trade.getTradeAmount()));
-                    summaryReceivedTextField.setText(BitSquareFormatter.formatVolume(trade.getOffer().getPrice() * BtcFormatter.satoshiToBTC(trade.getTradeAmount())));
-                    summaryFeesTextField.setText(BtcFormatter.formatSatoshis(FeePolicy.TAKE_OFFER_FEE.add(FeePolicy.TX_FEE)));
-                    summaryCollateralTextField.setText(BtcFormatter.formatSatoshis(trade.getCollateralAmount()));
+                    summaryPaidTextField.setText(BitSquareFormatter.formatCoinToBtcWithCode(trade.getTradeAmount()));
+                    summaryReceivedTextField.setText(BitSquareFormatter.formatVolume(trade.getOffer().getPrice() * trade.getTradeAmount().value));
+                    summaryFeesTextField.setText(BitSquareFormatter.formatCoinToBtcWithCode(FeePolicy.TAKE_OFFER_FEE.add(FeePolicy.TX_FEE)));
+                    summaryCollateralTextField.setText(BitSquareFormatter.formatCoinToBtcWithCode(trade.getCollateralAmount()));
                     summaryDepositTxIdTextField.setText(depositTxId);
                     summaryPayoutTxIdTextField.setText(payoutTxId);
                 }
@@ -261,7 +261,7 @@ public class TakerOfferController implements Initializable, ChildController
 
     private void applyCollateral()
     {
-        collateralTextField.setText(getFormattedCollateral());
+        collateralTextField.setText(getFormattedCollateralAsBtc());
     }
 
     private void applyVolume()
@@ -282,23 +282,31 @@ public class TakerOfferController implements Initializable, ChildController
 
     private String getFormattedTotal()
     {
-        return BitSquareFormatter.formatDouble(BtcFormatter.satoshiToBTC(getTotal()), 4);
+        return BitSquareFormatter.formatCoinToBtcWithCode(getTotal());
     }
 
-    private String getFormattedCollateral()
-    {
-        return BtcFormatter.formatSatoshis(getCollateralInSatoshis());
-    }
 
     //  values
     private double getAmountAsDouble()
     {
-        return BitSquareConverter.stringToDouble(amountTextField.getText());
+        return BitSquareConverter.stringToDouble(getAmountString());
     }
 
-    private BigInteger getAmountInSatoshis()
+    private Coin getAmountInSatoshis()
     {
-        return BtcFormatter.stringValueToSatoshis(amountTextField.getText());
+        return BitSquareFormatter.parseBtcToCoin(getAmountString());
+    }
+
+    private String getAmountString()
+    {
+        try
+        {
+            BitSquareValidator.textFieldsHasPositiveDoubleValueWithReset(amountTextField);
+            return amountTextField.getText();
+        } catch (BitSquareValidator.ValidationException e)
+        {
+            return "0";
+        }
     }
 
     private double getVolume()
@@ -306,23 +314,39 @@ public class TakerOfferController implements Initializable, ChildController
         return offer.getPrice() * getAmountAsDouble();
     }
 
-    private BigInteger getFee()
+    private Coin getFee()
     {
         return FeePolicy.TAKE_OFFER_FEE.add(FeePolicy.TX_FEE);
     }
 
-    private BigInteger getTotal()
+    private Coin getTotal()
     {
-        return getFee().add(getAmountInSatoshis()).add(getCollateralInSatoshis());
+        return getFee().add(getAmountInSatoshis()).add(getCollateralAsCoin());
     }
 
-    private BigInteger getCollateralInSatoshis()
+    private Coin getCollateralAsCoin()
     {
-        double amount = BitSquareConverter.stringToDouble(amountTextField.getText());
-        double resultDouble = amount * (double) offer.getCollateral() / 100.0;
-        return BtcFormatter.doubleValueToSatoshis(resultDouble);
+        Coin amountAsCoin = BitSquareFormatter.parseBtcToCoin(getAmountString());
+        return amountAsCoin.divide((long) (1d / offer.getCollateral()));
     }
 
+    private String getFormattedCollateralAsBtc()
+    {
+        Coin amountAsCoin = BitSquareFormatter.parseBtcToCoin(getAmountString());
+        Coin collateralAsCoin = amountAsCoin.divide((long) (1d / getCollateral()));
+        return BitSquareFormatter.formatCoinToBtc(collateralAsCoin);
+    }
+
+    private String getCollateralAsPercent()
+    {
+        return BitSquareFormatter.formatCollateralPercent(getCollateral());
+    }
+
+    private double getCollateral()
+    {
+        // TODO
+        return offer.getCollateral();
+    }
 
     public void setTradeId(String tradeId)
     {
diff --git a/src/main/java/io/bitsquare/gui/orders/offer/OfferListItem.java b/src/main/java/io/bitsquare/gui/orders/offer/OfferListItem.java
index 4e26c34891..231e1001f5 100644
--- a/src/main/java/io/bitsquare/gui/orders/offer/OfferListItem.java
+++ b/src/main/java/io/bitsquare/gui/orders/offer/OfferListItem.java
@@ -1,6 +1,5 @@
 package io.bitsquare.gui.orders.offer;
 
-import io.bitsquare.btc.BtcFormatter;
 import io.bitsquare.gui.util.BitSquareFormatter;
 import io.bitsquare.trade.Offer;
 import javafx.beans.property.SimpleStringProperty;
@@ -23,10 +22,7 @@ public class OfferListItem
         this.date.set(BitSquareFormatter.formatDateTime(offer.getCreationDate()));
         this.price.set(BitSquareFormatter.formatPrice(offer.getPrice()));
 
-        double amountAsBtcDouble = BtcFormatter.satoshiToBTC(offer.getAmount());
-        double minAmountAsBtcDouble = BtcFormatter.satoshiToBTC(offer.getMinAmount());
-        this.amount.set(BitSquareFormatter.formatAmountWithMinAmount(amountAsBtcDouble, minAmountAsBtcDouble));
-
+        this.amount.set(BitSquareFormatter.formatCoinToBtc(offer.getAmount()) + " (" + BitSquareFormatter.formatCoinToBtc(offer.getMinAmount()) + ")");
         this.volume.set(BitSquareFormatter.formatVolumeWithMinVolume(offer.getVolume(), offer.getMinVolume()));
         this.offerId = offer.getId();
     }
diff --git a/src/main/java/io/bitsquare/gui/orders/pending/PendingTradeController.java b/src/main/java/io/bitsquare/gui/orders/pending/PendingTradeController.java
index c98680d042..632901a80e 100644
--- a/src/main/java/io/bitsquare/gui/orders/pending/PendingTradeController.java
+++ b/src/main/java/io/bitsquare/gui/orders/pending/PendingTradeController.java
@@ -1,15 +1,11 @@
 package io.bitsquare.gui.orders.pending;
 
-import com.google.bitcoin.core.ECKey;
-import com.google.bitcoin.core.Transaction;
-import com.google.bitcoin.core.Wallet;
-import com.google.bitcoin.core.WalletEventListener;
+import com.google.bitcoin.core.*;
 import com.google.bitcoin.script.Script;
 import de.jensd.fx.fontawesome.AwesomeDude;
 import de.jensd.fx.fontawesome.AwesomeIcon;
 import io.bitsquare.bank.BankAccount;
 import io.bitsquare.bank.BankAccountType;
-import io.bitsquare.btc.BtcFormatter;
 import io.bitsquare.btc.FeePolicy;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.gui.ChildController;
@@ -26,7 +22,6 @@ import io.bitsquare.trade.Offer;
 import io.bitsquare.trade.Trade;
 import io.bitsquare.trade.Trading;
 import io.bitsquare.util.AWTSystemTray;
-import java.math.BigInteger;
 import java.net.URL;
 import java.util.*;
 import javafx.beans.property.ReadOnlyObjectWrapper;
@@ -54,6 +49,7 @@ public class PendingTradeController implements Initializable, ChildController, H
 
     private Trading trading;
     private WalletFacade walletFacade;
+
     private Trade currentTrade;
     private NavigationController navigationController;
     private Image buyIcon = Icons.getIconImage(Icons.BUY);
@@ -221,12 +217,12 @@ public class PendingTradeController implements Initializable, ChildController, H
             }
 
             @Override
-            public void onCoinsReceived(Wallet wallet, Transaction tx, BigInteger prevBalance, BigInteger newBalance)
+            public void onCoinsReceived(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance)
             {
             }
 
             @Override
-            public void onCoinsSent(Wallet wallet, Transaction tx, BigInteger prevBalance, BigInteger newBalance)
+            public void onCoinsSent(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance)
             {
             }
 
@@ -242,13 +238,14 @@ public class PendingTradeController implements Initializable, ChildController, H
             }
 
             @Override
-            public void onKeysAdded(Wallet wallet, List<ECKey> keys)
+            public void onScriptsAdded(Wallet wallet, List<Script> scripts)
             {
             }
 
             @Override
-            public void onScriptsAdded(Wallet wallet, List<Script> scripts)
+            public void onKeysAdded(List<ECKey> keys)
             {
+
             }
         });
     }
@@ -300,12 +297,13 @@ public class PendingTradeController implements Initializable, ChildController, H
             primaryBankAccountIDTitleLabel.setText("Total fees (offer fee + tx fee):");
             secondaryBankAccountIDTitleLabel.setText("Refunded collateral:");
 
-            String fiatPayed = BitSquareFormatter.formatVolume(trade.getOffer().getPrice() * BtcFormatter.satoshiToBTC(trade.getTradeAmount()));
+            //TODO
+            String fiatPayed = BitSquareFormatter.formatVolume(trade.getOffer().getPrice() * trade.getTradeAmount().value);
 
-            bankAccountTypeTextField.setText(BtcFormatter.formatSatoshis(trade.getTradeAmount()));
+            bankAccountTypeTextField.setText(BitSquareFormatter.formatCoinToBtcWithCode(trade.getTradeAmount()));
             holderNameTextField.setText(fiatPayed);
-            primaryBankAccountIDTextField.setText(BtcFormatter.formatSatoshis(FeePolicy.CREATE_OFFER_FEE.add(FeePolicy.TX_FEE)));
-            secondaryBankAccountIDTextField.setText(BtcFormatter.formatSatoshis(trade.getCollateralAmount()));
+            primaryBankAccountIDTextField.setText(BitSquareFormatter.formatCoinToBtcWithCode(FeePolicy.CREATE_OFFER_FEE.add(FeePolicy.TX_FEE)));
+            secondaryBankAccountIDTextField.setText(BitSquareFormatter.formatCoinToBtcWithCode(trade.getCollateralAmount()));
 
             holderNameCopyIcon.setVisible(false);
             primaryBankAccountIDCopyIcon.setVisible(false);
diff --git a/src/main/java/io/bitsquare/gui/settings/SettingsController.java b/src/main/java/io/bitsquare/gui/settings/SettingsController.java
index 073d903da0..820027957a 100644
--- a/src/main/java/io/bitsquare/gui/settings/SettingsController.java
+++ b/src/main/java/io/bitsquare/gui/settings/SettingsController.java
@@ -138,7 +138,7 @@ public class SettingsController implements Initializable, ChildController, Navig
     {
         if (settings.getAcceptedArbitrators().isEmpty())
         {
-            String pubKeyAsHex = Utils.bytesToHexString(new ECKey().getPubKey());
+            String pubKeyAsHex = Utils.HEX.encode(new ECKey().getPubKey());
             String messagePubKeyAsHex = DSAKeyUtil.getHexStringFromPublicKey(user.getMessagePublicKey());
             List<Locale> languages = new ArrayList<>();
             languages.add(LanguageUtil.getDefaultLanguageLocale());
@@ -603,6 +603,7 @@ public class SettingsController implements Initializable, ChildController, Navig
         persistence.write(user);
     }
 
+
     ///////////////////////////////////////////////////////////////////////////////////////////
     // Bank Account Settings
     ///////////////////////////////////////////////////////////////////////////////////////////
diff --git a/src/main/java/io/bitsquare/gui/util/BitSquareFormatter.java b/src/main/java/io/bitsquare/gui/util/BitSquareFormatter.java
index b1d8721f3e..48b3c5d49f 100644
--- a/src/main/java/io/bitsquare/gui/util/BitSquareFormatter.java
+++ b/src/main/java/io/bitsquare/gui/util/BitSquareFormatter.java
@@ -1,99 +1,86 @@
 package io.bitsquare.gui.util;
 
+import com.google.bitcoin.core.Coin;
 import io.bitsquare.locale.Country;
 import io.bitsquare.locale.Localisation;
 import io.bitsquare.trade.Direction;
 import io.bitsquare.user.Arbitrator;
 import java.text.DateFormat;
 import java.text.DecimalFormat;
-import java.util.Currency;
 import java.util.Date;
 import java.util.List;
 import java.util.Locale;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
-@SuppressWarnings("WeakerAccess")
+//TODO cleanup...
 public class BitSquareFormatter
 {
+    private static final Logger log = LoggerFactory.getLogger(BitSquareFormatter.class);
+
+    ///////////////////////////////////////////////////////////////////////////////////////////
+    // BTC
+    ///////////////////////////////////////////////////////////////////////////////////////////
+
+    public static String formatCoinToBtc(Coin coin)
+    {
+        return coin.toFriendlyString();
+    }
+
+   /* public static String formatCoinToBtcWithSymbol(Coin coin)
+    {
+        return "฿ " + coin.toPlainString();
+    } */
+
+    public static String formatCoinToBtcWithCode(Coin coin)
+    {
+        return coin.toFriendlyString();
+    }
+
+    /**
+     * @param input String input in decimal or integer format. Both decimal marks (",", ".") are supported.
+     *              If input has an incorrect format it returns a zero value coin.
+     * @return
+     */
+    public static Coin parseBtcToCoin(String input)
+    {
+        try
+        {
+            input = input.replace(",", ".");
+            Double.parseDouble(input);
+
+        } catch (NumberFormatException | NullPointerException e)
+        {
+            log.warn("Exception at parseBtcToCoin: " + e.toString());
+            input = "0";
+        }
+        return Coin.parseCoin(input);
+    }
+
+
+    ///////////////////////////////////////////////////////////////////////////////////////////
+    // FIAT
+    ///////////////////////////////////////////////////////////////////////////////////////////
+
     public static String formatPrice(double price)
     {
         return formatDouble(price);
     }
 
-
-    public static String formatPriceWithCurrencyPair(double price, Currency currency)
-    {
-        return formatDouble(price) + " " + currency + "/BTC";
-    }
-
-    @SuppressWarnings("SameParameterValue")
-
-    public static String formatAmount(double amount, boolean useBTC, boolean exact)
-    {
-        return formatDouble(amount, (exact ? 4 : 2)) + (useBTC ? " BTC" : "");
-    }
-
-    @SuppressWarnings("SameParameterValue")
-
-    public static String formatAmount(double amount, boolean useBTC)
-    {
-        return formatAmount(amount, useBTC, false);
-    }
-
-
-    public static String formatAmount(double amount)
-    {
-        return formatAmount(amount, false);
-    }
-
-    @SuppressWarnings("SameParameterValue")
-
-    public static String formatAmountWithMinAmount(double amount, double minAmount, boolean useBTC)
-    {
-        if (useBTC)
-        {
-            return formatDouble(amount) + " BTC (" + formatDouble(minAmount) + " BTC)";
-        }
-        else
-        {
-            return formatDouble(amount) + " (" + formatDouble(minAmount) + ")";
-        }
-    }
-
-
-    public static String formatAmountWithMinAmount(double amount, double minAmount)
-    {
-        return formatAmountWithMinAmount(amount, minAmount, false);
-    }
-
     public static String formatVolume(double volume)
     {
         return formatDouble(volume);
     }
 
-
-    public static String formatVolume(double volume, Currency currency)
-    {
-        return formatDouble(volume) + " " + currency;
-    }
-
-
-    public static String formatVolumeWithMinVolume(double volume, double minVolume, Currency currency)
-    {
-        return formatDouble(volume) + " " + currency + " (" + formatDouble(minVolume) + " " + currency + ")";
-    }
-
-
     public static String formatVolumeWithMinVolume(double volume, double minVolume)
     {
         return formatDouble(volume) + " (" + formatDouble(minVolume) + ")";
     }
 
 
-    public static String formatCollateral(double collateral, double amount)
-    {
-        return formatPercent(collateral) + " (" + formatDouble(collateral * amount, 4) + " BTC)";
-    }
-
+    ///////////////////////////////////////////////////////////////////////////////////////////
+    // Other
+    ///////////////////////////////////////////////////////////////////////////////////////////
 
     public static String formatDirection(Direction direction, boolean allUpperCase)
     {
@@ -105,13 +92,6 @@ public class BitSquareFormatter
         return result;
     }
 
-
-    public static String formatList(List<String> list)
-    {
-        String s = list.toString();
-        return s.substring(1, s.length() - 1);
-    }
-
     public static String formatDouble(double value)
     {
         return formatDouble(value, 2);
@@ -123,7 +103,6 @@ public class BitSquareFormatter
         return decimalFormat.format(value);
     }
 
-
     public static DecimalFormat getDecimalFormat(int fractionDigits)
     {
         DecimalFormat decimalFormat = (DecimalFormat) DecimalFormat.getInstance(Locale.getDefault());
@@ -133,13 +112,6 @@ public class BitSquareFormatter
         return decimalFormat;
     }
 
-
-    private static String formatPercent(double value)
-    {
-        return value * 100 + "%";
-    }
-
-
     public static String countryLocalesToString(List<Country> countries)
     {
         String result = "";
@@ -206,7 +178,6 @@ public class BitSquareFormatter
         return result;
     }
 
-
     public static String formatDateTime(Date date)
     {
         DateFormat dateFormatter = DateFormat.getDateInstance(DateFormat.DEFAULT, Locale.getDefault());
@@ -214,5 +185,8 @@ public class BitSquareFormatter
         return dateFormatter.format(date) + " " + timeFormatter.format(date);
     }
 
-
+    public static String formatCollateralPercent(double collateral)
+    {
+        return getDecimalFormat(2).format(collateral * 100) + " %";
+    }
 }
diff --git a/src/main/java/io/bitsquare/gui/util/BitSquareValidator.java b/src/main/java/io/bitsquare/gui/util/BitSquareValidator.java
index 0ba07f159e..76da076eec 100644
--- a/src/main/java/io/bitsquare/gui/util/BitSquareValidator.java
+++ b/src/main/java/io/bitsquare/gui/util/BitSquareValidator.java
@@ -1,8 +1,8 @@
 package io.bitsquare.gui.util;
 
+import com.google.bitcoin.core.Coin;
 import io.bitsquare.bank.BankAccountType;
 import io.bitsquare.trade.Offer;
-import java.math.BigInteger;
 import javafx.scene.control.TextField;
 import javafx.scene.effect.BlurType;
 import javafx.scene.effect.DropShadow;
@@ -15,14 +15,14 @@ public class BitSquareValidator
     private static final Effect invalidEffect = new DropShadow(BlurType.GAUSSIAN, Color.RED, 4, 0.0, 0, 0);
     private static final String invalidStyle = "-fx-border-color: red";
 
-    public static boolean tradeAmountOutOfRange(BigInteger tradeAmount, Offer offer)
+    public static boolean tradeAmountOutOfRange(Coin tradeAmount, Offer offer)
     {
         return tradeAmount.compareTo(offer.getAmount()) > 0 || tradeAmount.compareTo(offer.getMinAmount()) < 0;
     }
 
-    public static boolean greaterThanZero(BigInteger value)
+    public static boolean greaterThanZero(Coin value)
     {
-        return value.compareTo(BigInteger.ZERO) > 0;
+        return value.compareTo(Coin.ZERO) > 0;
     }
 
     public static void textFieldsNotEmptyWithReset(TextField... textFields) throws ValidationException
@@ -74,7 +74,7 @@ public class BitSquareValidator
 
     public static void textFieldHasDoubleValue(TextField textField) throws ValidationException
     {
-        if (!validateStringAsDouble(textField.getText()))
+        if (!validateStringAsDouble(textField.getText().replace(",", ".")))
         {
             textField.setEffect(invalidEffect);
             textField.setStyle(invalidStyle);
@@ -82,6 +82,42 @@ public class BitSquareValidator
         }
     }
 
+
+    public static void textFieldsHasPositiveDoubleValueWithReset(TextField... textFields) throws ValidationException
+    {
+        resetTextFields(textFields);
+        textFieldsHasPositiveDoubleValue(textFields);
+    }
+
+    public static void textFieldsHasPositiveDoubleValue(TextField... textFields) throws ValidationException
+    {
+        for (TextField textField : textFields)
+        {
+            textFieldHasPositiveDoubleValue(textField);
+        }
+    }
+
+    public static void textFieldHasPositiveDoubleValue(TextField textField) throws ValidationException
+    {
+        String input = textField.getText().replace(",", ".");
+        if (!validateStringAsDouble(input))
+        {
+            textField.setEffect(invalidEffect);
+            textField.setStyle(invalidStyle);
+            throw new ValidationException();
+        }
+        else
+        {
+            double val = Double.parseDouble(input);
+            if (val <= 0)
+            {
+                textField.setEffect(invalidEffect);
+                textField.setStyle(invalidStyle);
+                throw new ValidationException();
+            }
+        }
+    }
+
     //TODO
     @SuppressWarnings("UnusedParameters")
     public static void textFieldBankAccountPrimaryIDIsValid(TextField textField, BankAccountType bankAccountType) throws ValidationException
diff --git a/src/main/java/io/bitsquare/gui/util/ConfidenceDisplay.java b/src/main/java/io/bitsquare/gui/util/ConfidenceDisplay.java
index 6bb21d2292..39bd05646a 100644
--- a/src/main/java/io/bitsquare/gui/util/ConfidenceDisplay.java
+++ b/src/main/java/io/bitsquare/gui/util/ConfidenceDisplay.java
@@ -2,9 +2,7 @@ package io.bitsquare.gui.util;
 
 import com.google.bitcoin.core.*;
 import com.google.bitcoin.script.Script;
-import io.bitsquare.btc.BtcFormatter;
 import io.bitsquare.gui.components.confidence.ConfidenceProgressIndicator;
-import java.math.BigInteger;
 import java.util.List;
 import java.util.Set;
 import javafx.scene.control.Label;
@@ -45,12 +43,24 @@ public class ConfidenceDisplay
         walletEventListener = new WalletEventListener()
         {
             @Override
-            public void onCoinsReceived(Wallet wallet, Transaction tx, BigInteger prevBalance, BigInteger newBalance)
+            public void onCoinsReceived(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance)
             {
                 updateBalance(newBalance);
                 // log.debug("onCoinsReceived  " + newBalance);
             }
 
+            @Override
+            public void onCoinsSent(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance)
+            {
+                updateBalance(newBalance);
+            }
+
+            @Override
+            public void onReorganize(Wallet wallet)
+            {
+
+            }
+
             @Override
             public void onTransactionConfidenceChanged(Wallet wallet, Transaction tx)
             {
@@ -58,30 +68,22 @@ public class ConfidenceDisplay
                 // log.debug("onTransactionConfidenceChanged tx " + tx.getHashAsString());
             }
 
-            @Override
-            public void onCoinsSent(Wallet wallet, Transaction tx, BigInteger prevBalance, BigInteger newBalance)
-            {
-                updateBalance(newBalance);
-            }
-
-            @Override
-            public void onReorganize(Wallet wallet)
-            {
-            }
-
             @Override
             public void onWalletChanged(Wallet wallet)
             {
-            }
 
-            @Override
-            public void onKeysAdded(Wallet wallet, List<ECKey> keys)
-            {
             }
 
             @Override
             public void onScriptsAdded(Wallet wallet, List<Script> scripts)
             {
+
+            }
+
+            @Override
+            public void onKeysAdded(List<ECKey> keys)
+            {
+
             }
         };
         wallet.addEventListener(walletEventListener);
@@ -104,7 +106,7 @@ public class ConfidenceDisplay
         walletEventListener = new WalletEventListener()
         {
             @Override
-            public void onCoinsReceived(Wallet wallet, Transaction tx, BigInteger prevBalance, BigInteger newBalance)
+            public void onCoinsReceived(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance)
             {
                 if (tx.getHashAsString().equals(transaction.getHashAsString()))
                 {
@@ -113,6 +115,21 @@ public class ConfidenceDisplay
                 // log.debug("onCoinsReceived " + newBalance);
             }
 
+            @Override
+            public void onCoinsSent(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance)
+            {
+                if (tx.getHashAsString().equals(transaction.getHashAsString()))
+                {
+                    updateBalance(newBalance);
+                }
+            }
+
+            @Override
+            public void onReorganize(Wallet wallet)
+            {
+
+            }
+
             @Override
             public void onTransactionConfidenceChanged(Wallet wallet, Transaction tx)
             {
@@ -123,33 +140,22 @@ public class ConfidenceDisplay
                 // log.debug("onTransactionConfidenceChanged newTransaction " + newTransaction.getHashAsString());
             }
 
-            @Override
-            public void onCoinsSent(Wallet wallet, Transaction tx, BigInteger prevBalance, BigInteger newBalance)
-            {
-                if (tx.getHashAsString().equals(transaction.getHashAsString()))
-                {
-                    updateBalance(newBalance);
-                }
-            }
-
-            @Override
-            public void onReorganize(Wallet wallet)
-            {
-            }
-
             @Override
             public void onWalletChanged(Wallet wallet)
             {
-            }
 
-            @Override
-            public void onKeysAdded(Wallet wallet, List<ECKey> keys)
-            {
             }
 
             @Override
             public void onScriptsAdded(Wallet wallet, List<Script> scripts)
             {
+
+            }
+
+            @Override
+            public void onKeysAdded(List<ECKey> keys)
+            {
+
             }
         };
         wallet.addEventListener(walletEventListener);
@@ -166,9 +172,9 @@ public class ConfidenceDisplay
         }
     }
 
-    private void updateBalance(BigInteger balance)
+    private void updateBalance(Coin balance)
     {
-        if (balance.compareTo(BigInteger.ZERO) > 0)
+        if (balance.compareTo(Coin.ZERO) > 0)
         {
             confirmationLabel.setVisible(true);
             progressIndicator.setVisible(true);
@@ -198,7 +204,8 @@ public class ConfidenceDisplay
 
         if (balanceTextField != null)
         {
-            balanceTextField.setText(BtcFormatter.formatSatoshis(balance));
+            //TODO
+            balanceTextField.setText(balance.toFriendlyString());
         }
     }
 
diff --git a/src/main/java/io/bitsquare/msg/P2PNode.java b/src/main/java/io/bitsquare/msg/P2PNode.java
index f04aee2191..e942b682cb 100644
--- a/src/main/java/io/bitsquare/msg/P2PNode.java
+++ b/src/main/java/io/bitsquare/msg/P2PNode.java
@@ -44,7 +44,7 @@ public class P2PNode
     // just for lightweight client test
     public static void main(String[] args)
     {
-        P2PNode p2pNode = new P2PNode(DSAKeyUtil.generateKeyPair(), false, SeedNodeAddress.StaticSeedNodeAddresses.LOCALHOST,
+        P2PNode p2pNode = new P2PNode(DSAKeyUtil.generateKeyPair(), false, SeedNodeAddress.StaticSeedNodeAddresses.DIGITAL_OCEAN,
                                       (message, peerAddress) -> log.debug("handleMessage: message= " + message + "/ peerAddress=" + peerAddress));
         p2pNode.start(new FutureCallback<PeerDHT>()
         {
diff --git a/src/main/java/io/bitsquare/settings/Settings.java b/src/main/java/io/bitsquare/settings/Settings.java
index 4e2ecf83d9..5524a6ac7c 100644
--- a/src/main/java/io/bitsquare/settings/Settings.java
+++ b/src/main/java/io/bitsquare/settings/Settings.java
@@ -1,9 +1,9 @@
 package io.bitsquare.settings;
 
+import com.google.bitcoin.core.Coin;
 import io.bitsquare.locale.Country;
 import io.bitsquare.user.Arbitrator;
 import java.io.Serializable;
-import java.math.BigInteger;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
@@ -16,8 +16,7 @@ public class Settings implements Serializable
     private List<Locale> acceptedLanguageLocales = new ArrayList<>();
     private List<Country> acceptedCountryLocales = new ArrayList<>();
     private List<Arbitrator> acceptedArbitrators = new ArrayList<>();
-    private int maxCollateral;
-    private int minCollateral;
+    private double collateral = 0.01;
 
 
     ///////////////////////////////////////////////////////////////////////////////////////////
@@ -40,8 +39,7 @@ public class Settings implements Serializable
             acceptedLanguageLocales = persistedSettings.getAcceptedLanguageLocales();
             acceptedCountryLocales = persistedSettings.getAcceptedCountries();
             acceptedArbitrators = persistedSettings.getAcceptedArbitrators();
-            maxCollateral = persistedSettings.getMaxCollateral();
-            minCollateral = persistedSettings.getMinCollateral();
+            collateral = persistedSettings.getCollateral();
         }
     }
 
@@ -110,7 +108,7 @@ public class Settings implements Serializable
     //TODO
     @SuppressWarnings("UnusedParameters")
 
-    public Arbitrator getRandomArbitrator(@SuppressWarnings("UnusedParameters") Integer collateral, @SuppressWarnings("UnusedParameters") BigInteger amount)
+    public Arbitrator getRandomArbitrator(@SuppressWarnings("UnusedParameters") double collateral, @SuppressWarnings("UnusedParameters") Coin amount)
     {
         List<Arbitrator> candidates = new ArrayList<>();
         //noinspection Convert2streamapi
@@ -125,24 +123,10 @@ public class Settings implements Serializable
         return !candidates.isEmpty() ? candidates.get((int) (Math.random() * candidates.size())) : null;
     }
 
-    int getMaxCollateral()
-    {
-        return maxCollateral;
-    }
 
-    public void setMaxCollateral(int maxCollateral)
+    public double getCollateral()
     {
-        this.maxCollateral = maxCollateral;
-    }
-
-    public int getMinCollateral()
-    {
-        return minCollateral;
-    }
-
-    public void setMinCollateral(int minCollateral)
-    {
-        this.minCollateral = minCollateral;
+        return collateral;
     }
 
 }
diff --git a/src/main/java/io/bitsquare/trade/Contract.java b/src/main/java/io/bitsquare/trade/Contract.java
index f0736510a4..cffc4f6d81 100644
--- a/src/main/java/io/bitsquare/trade/Contract.java
+++ b/src/main/java/io/bitsquare/trade/Contract.java
@@ -1,9 +1,9 @@
 package io.bitsquare.trade;
 
+import com.google.bitcoin.core.Coin;
 import io.bitsquare.bank.BankAccount;
 import io.bitsquare.util.DSAKeyUtil;
 import java.io.Serializable;
-import java.math.BigInteger;
 import java.security.PublicKey;
 
 public class Contract implements Serializable
@@ -12,7 +12,7 @@ public class Contract implements Serializable
 
     private final Offer offer;
     private final String takeOfferFeeTxID;
-    private final BigInteger tradeAmount;
+    private final Coin tradeAmount;
     private final String offererAccountID;
     private final String takerAccountID;
     private final BankAccount offererBankAccount;
@@ -21,7 +21,7 @@ public class Contract implements Serializable
     private final String takerMessagePublicKeyAsString;
 
     public Contract(Offer offer,
-                    BigInteger tradeAmount,
+                    Coin tradeAmount,
                     String takeOfferFeeTxID,
                     String offererAccountID,
                     String takerAccountID,
@@ -56,7 +56,7 @@ public class Contract implements Serializable
         return takeOfferFeeTxID;
     }
 
-    public BigInteger getTradeAmount()
+    public Coin getTradeAmount()
     {
         return tradeAmount;
     }
diff --git a/src/main/java/io/bitsquare/trade/Offer.java b/src/main/java/io/bitsquare/trade/Offer.java
index f0f7f13371..52bd41e767 100644
--- a/src/main/java/io/bitsquare/trade/Offer.java
+++ b/src/main/java/io/bitsquare/trade/Offer.java
@@ -1,11 +1,10 @@
 package io.bitsquare.trade;
 
+import com.google.bitcoin.core.Coin;
 import io.bitsquare.bank.BankAccountType;
-import io.bitsquare.btc.BtcFormatter;
 import io.bitsquare.locale.Country;
 import io.bitsquare.user.Arbitrator;
 import java.io.Serializable;
-import java.math.BigInteger;
 import java.security.PublicKey;
 import java.util.*;
 
@@ -22,13 +21,13 @@ public class Offer implements Serializable
     private final Date creationDate;
 
     private final double price;
-    private final BigInteger amount;
-    private final BigInteger minAmount;
+    private final Coin amount;
+    private final Coin minAmount;
     private final PublicKey messagePublicKey;
     private final BankAccountType bankAccountType;
     private final Country bankAccountCountry;
 
-    private final int collateral;
+    private final double collateral;
     private final List<Country> acceptedCountries;
     private final List<Locale> acceptedLanguageLocales;
     private final String bankAccountUID;
@@ -43,14 +42,14 @@ public class Offer implements Serializable
     public Offer(PublicKey messagePublicKey,
                  Direction direction,
                  double price,
-                 BigInteger amount,
-                 BigInteger minAmount,
+                 Coin amount,
+                 Coin minAmount,
                  BankAccountType bankAccountType,
                  Currency currency,
                  Country bankAccountCountry,
                  String bankAccountUID,
                  Arbitrator arbitrator,
-                 int collateral,
+                 double collateral,
                  List<Country> acceptedCountries,
                  List<Locale> acceptedLanguageLocales)
     {
@@ -98,12 +97,12 @@ public class Offer implements Serializable
         return price;
     }
 
-    public BigInteger getAmount()
+    public Coin getAmount()
     {
         return amount;
     }
 
-    public BigInteger getMinAmount()
+    public Coin getMinAmount()
     {
         return minAmount;
     }
@@ -140,12 +139,12 @@ public class Offer implements Serializable
 
     public double getVolume()
     {
-        return price * BtcFormatter.satoshiToBTC(amount);
+        return price * amount.value;
     }
 
     public double getMinVolume()
     {
-        return price * BtcFormatter.satoshiToBTC(minAmount);
+        return price * minAmount.value;
     }
 
     public String getOfferFeePaymentTxID()
@@ -163,7 +162,7 @@ public class Offer implements Serializable
         return arbitrator;
     }
 
-    public int getCollateral()
+    public double getCollateral()
     {
         return collateral;
     }
diff --git a/src/main/java/io/bitsquare/trade/Trade.java b/src/main/java/io/bitsquare/trade/Trade.java
index 3bae26e553..097963abe9 100644
--- a/src/main/java/io/bitsquare/trade/Trade.java
+++ b/src/main/java/io/bitsquare/trade/Trade.java
@@ -1,8 +1,8 @@
 package io.bitsquare.trade;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.Transaction;
 import java.io.Serializable;
-import java.math.BigInteger;
 import javafx.beans.property.SimpleBooleanProperty;
 import javafx.beans.property.SimpleStringProperty;
 
@@ -12,7 +12,7 @@ public class Trade implements Serializable
 
     private final Offer offer;
     private String takeOfferFeeTxID;
-    private BigInteger tradeAmount;
+    private Coin tradeAmount;
     private Contract contract;
     private String contractAsJson;
     private String takerSignature;
@@ -53,12 +53,12 @@ public class Trade implements Serializable
         this.takeOfferFeeTxID = takeOfferFeeTxID;
     }
 
-    public BigInteger getTradeAmount()
+    public Coin getTradeAmount()
     {
         return tradeAmount;
     }
 
-    public void setTradeAmount(BigInteger tradeAmount)
+    public void setTradeAmount(Coin tradeAmount)
     {
         this.tradeAmount = tradeAmount;
     }
@@ -172,9 +172,9 @@ public class Trade implements Serializable
         return _stateChangedProperty;
     }
 
-    public BigInteger getCollateralAmount()
+    public Coin getCollateralAmount()
     {
-        return getTradeAmount().multiply(BigInteger.valueOf(getOffer().getCollateral())).divide(BigInteger.valueOf(100));
+        return tradeAmount.divide((long) (1d / offer.getCollateral()));
     }
 
 
diff --git a/src/main/java/io/bitsquare/trade/Trading.java b/src/main/java/io/bitsquare/trade/Trading.java
index 680f8a3cb8..22295ee8ae 100644
--- a/src/main/java/io/bitsquare/trade/Trading.java
+++ b/src/main/java/io/bitsquare/trade/Trading.java
@@ -1,5 +1,6 @@
 package io.bitsquare.trade;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.Transaction;
 import com.google.bitcoin.core.TransactionConfidence;
 import com.google.bitcoin.core.Utils;
@@ -15,7 +16,6 @@ import io.bitsquare.trade.protocol.offerer.*;
 import io.bitsquare.trade.protocol.taker.*;
 import io.bitsquare.user.User;
 import java.io.IOException;
-import java.math.BigInteger;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -146,7 +146,7 @@ public class Trading
         messageFacade.removeOffer(offer);
     }
 
-    public Trade takeOffer(BigInteger amount, Offer offer, ProtocolForTakerAsSellerListener listener)
+    public Trade takeOffer(Coin amount, Offer offer, ProtocolForTakerAsSellerListener listener)
     {
         Trade trade = createTrade(offer);
         trade.setTradeAmount(amount);
diff --git a/src/main/java/io/bitsquare/trade/orderbook/OrderBook.java b/src/main/java/io/bitsquare/trade/orderbook/OrderBook.java
index e26d008b7a..55c6253f8b 100644
--- a/src/main/java/io/bitsquare/trade/orderbook/OrderBook.java
+++ b/src/main/java/io/bitsquare/trade/orderbook/OrderBook.java
@@ -115,7 +115,8 @@ public class OrderBook implements OrderBookListener
             boolean amountResult = true;
             if (orderBookFilter.getAmount() > 0)
             {
-                amountResult = orderBookFilter.getAmount() <= offer.getAmount().doubleValue();
+                //TODO
+                amountResult = orderBookFilter.getAmount() <= offer.getAmount().value;
             }
 
             // The requested trade direction must be opposite of the offerList trade direction
diff --git a/src/main/java/io/bitsquare/trade/protocol/offerer/BankTransferInitedMessage.java b/src/main/java/io/bitsquare/trade/protocol/offerer/BankTransferInitedMessage.java
index 8f7a530050..520ab130c9 100644
--- a/src/main/java/io/bitsquare/trade/protocol/offerer/BankTransferInitedMessage.java
+++ b/src/main/java/io/bitsquare/trade/protocol/offerer/BankTransferInitedMessage.java
@@ -1,8 +1,8 @@
 package io.bitsquare.trade.protocol.offerer;
 
+import com.google.bitcoin.core.Coin;
 import io.bitsquare.trade.protocol.TradeMessage;
 import java.io.Serializable;
-import java.math.BigInteger;
 
 public class BankTransferInitedMessage implements Serializable, TradeMessage
 {
@@ -12,16 +12,16 @@ public class BankTransferInitedMessage implements Serializable, TradeMessage
     private String depositTxAsHex;
     private String offererSignatureR;
     private String offererSignatureS;
-    private BigInteger offererPaybackAmount;
-    private BigInteger takerPaybackAmount;
+    private Coin offererPaybackAmount;
+    private Coin takerPaybackAmount;
     private String offererPayoutAddress;
 
     public BankTransferInitedMessage(String tradeId,
                                      String depositTxAsHex,
                                      String offererSignatureR,
                                      String offererSignatureS,
-                                     BigInteger offererPaybackAmount,
-                                     BigInteger takerPaybackAmount,
+                                     Coin offererPaybackAmount,
+                                     Coin takerPaybackAmount,
                                      String offererPayoutAddress)
     {
         this.tradeId = tradeId;
@@ -54,12 +54,12 @@ public class BankTransferInitedMessage implements Serializable, TradeMessage
         return offererSignatureS;
     }
 
-    public BigInteger getOffererPaybackAmount()
+    public Coin getOffererPaybackAmount()
     {
         return offererPaybackAmount;
     }
 
-    public BigInteger getTakerPaybackAmount()
+    public Coin getTakerPaybackAmount()
     {
         return takerPaybackAmount;
     }
diff --git a/src/main/java/io/bitsquare/trade/protocol/offerer/CreateDepositTx.java b/src/main/java/io/bitsquare/trade/protocol/offerer/CreateDepositTx.java
index 4638d394c9..acf089e3cc 100644
--- a/src/main/java/io/bitsquare/trade/protocol/offerer/CreateDepositTx.java
+++ b/src/main/java/io/bitsquare/trade/protocol/offerer/CreateDepositTx.java
@@ -1,11 +1,11 @@
 package io.bitsquare.trade.protocol.offerer;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.InsufficientMoneyException;
 import com.google.bitcoin.core.Transaction;
 import com.google.bitcoin.core.Utils;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.trade.protocol.FaultHandler;
-import java.math.BigInteger;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -17,7 +17,7 @@ public class CreateDepositTx
                            FaultHandler faultHandler,
                            WalletFacade walletFacade,
                            String tradeId,
-                           BigInteger offererInputAmount,
+                           Coin offererInputAmount,
                            String takerMultiSigPubKey,
                            String arbitratorPubKeyAsHex)
     {
@@ -27,7 +27,7 @@ public class CreateDepositTx
             String offererPubKey = walletFacade.getAddressInfoByTradeID(tradeId).getPubKeyAsHexString();
             Transaction transaction = walletFacade.offererCreatesMSTxAndAddPayment(offererInputAmount, offererPubKey, takerMultiSigPubKey, arbitratorPubKeyAsHex, tradeId);
 
-            String preparedOffererDepositTxAsHex = Utils.bytesToHexString(transaction.bitcoinSerialize());
+            String preparedOffererDepositTxAsHex = Utils.HEX.encode(transaction.bitcoinSerialize());
             long offererTxOutIndex = transaction.getInput(0).getOutpoint().getIndex();
 
             resultHandler.onResult(offererPubKey, preparedOffererDepositTxAsHex, offererTxOutIndex);
diff --git a/src/main/java/io/bitsquare/trade/protocol/offerer/ProtocolForOffererAsBuyer.java b/src/main/java/io/bitsquare/trade/protocol/offerer/ProtocolForOffererAsBuyer.java
index 48412736be..5d3a53f934 100644
--- a/src/main/java/io/bitsquare/trade/protocol/offerer/ProtocolForOffererAsBuyer.java
+++ b/src/main/java/io/bitsquare/trade/protocol/offerer/ProtocolForOffererAsBuyer.java
@@ -1,5 +1,6 @@
 package io.bitsquare.trade.protocol.offerer;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.ECKey;
 import com.google.bitcoin.core.Transaction;
 import io.bitsquare.bank.BankAccount;
@@ -15,7 +16,6 @@ import io.bitsquare.trade.protocol.taker.PayoutTxPublishedMessage;
 import io.bitsquare.trade.protocol.taker.RequestOffererPublishDepositTxMessage;
 import io.bitsquare.trade.protocol.taker.TakeOfferFeePayedMessage;
 import io.bitsquare.user.User;
-import java.math.BigInteger;
 import java.security.PublicKey;
 import net.tomp2p.peers.PeerAddress;
 import org.jetbrains.annotations.NotNull;
@@ -176,7 +176,7 @@ public class ProtocolForOffererAsBuyer
         checkState(state == State.HandleTakeOfferRequest);
         checkArgument(tradeId.equals(message.getTradeId()));
         String takeOfferFeeTxId = nonEmptyStringOf(message.getTakeOfferFeeTxId());
-        BigInteger tradeAmount = nonNegativeBigIntegerOf(nonZeroBigIntegerOf(message.getTradeAmount()));
+        Coin tradeAmount = positiveCoinOf(nonZeroCoinOf(message.getTradeAmount()));
         String takerPubKey = nonEmptyStringOf(message.getTakerPubKey());
 
         // apply new state
@@ -195,8 +195,8 @@ public class ProtocolForOffererAsBuyer
     {
         log.debug("onResultVerifyTakeOfferFeePayment called " + step++);
 
-        BigInteger collateral = trade.getCollateralAmount();
-        BigInteger offererInputAmount = collateral.add(FeePolicy.TX_FEE);
+        Coin collateral = trade.getCollateralAmount();
+        Coin offererInputAmount = collateral.add(FeePolicy.TX_FEE);
         state = State.CreateDepositTx;
         CreateDepositTx.run(this::onResultCreateDepositTx, this::onFault, walletFacade, tradeId, offererInputAmount, takerPubKey, arbitratorPubKey);
     }
@@ -270,7 +270,7 @@ public class ProtocolForOffererAsBuyer
     {
         log.debug("onResultVerifyTakerAccount called " + step++);
 
-        BigInteger tradeAmount = trade.getTradeAmount();
+        Coin tradeAmount = trade.getTradeAmount();
         state = State.VerifyAndSignContract;
         VerifyAndSignContract.run(this::onResultVerifyAndSignContract,
                                   this::onFault,
@@ -352,8 +352,8 @@ public class ProtocolForOffererAsBuyer
 
         // next task
         String depositTransactionId = trade.getDepositTransaction().getHashAsString();
-        BigInteger tradeAmount = trade.getTradeAmount();
-        BigInteger collateral = trade.getCollateralAmount();
+        Coin tradeAmount = trade.getTradeAmount();
+        Coin collateral = trade.getCollateralAmount();
         state = State.SendSignedPayoutTx;
         SendSignedPayoutTx.run(this::onResultSendSignedPayoutTx,
                                this::onFault,
diff --git a/src/main/java/io/bitsquare/trade/protocol/offerer/SendDepositTxIdToTaker.java b/src/main/java/io/bitsquare/trade/protocol/offerer/SendDepositTxIdToTaker.java
index c374020b3b..9d9d223c2b 100644
--- a/src/main/java/io/bitsquare/trade/protocol/offerer/SendDepositTxIdToTaker.java
+++ b/src/main/java/io/bitsquare/trade/protocol/offerer/SendDepositTxIdToTaker.java
@@ -17,7 +17,7 @@ public class SendDepositTxIdToTaker
     public static void run(ResultHandler resultHandler, FaultHandler faultHandler, PeerAddress peerAddress, MessageFacade messageFacade, String tradeId, Transaction depositTransaction)
     {
         log.trace("Run task");
-        DepositTxPublishedMessage tradeMessage = new DepositTxPublishedMessage(tradeId, Utils.bytesToHexString(depositTransaction.bitcoinSerialize()));
+        DepositTxPublishedMessage tradeMessage = new DepositTxPublishedMessage(tradeId, Utils.HEX.encode(depositTransaction.bitcoinSerialize()));
         messageFacade.sendTradeMessage(peerAddress, tradeMessage, new OutgoingTradeMessageListener()
         {
             @Override
diff --git a/src/main/java/io/bitsquare/trade/protocol/offerer/SendSignedPayoutTx.java b/src/main/java/io/bitsquare/trade/protocol/offerer/SendSignedPayoutTx.java
index 88c62ca6dd..352daac073 100644
--- a/src/main/java/io/bitsquare/trade/protocol/offerer/SendSignedPayoutTx.java
+++ b/src/main/java/io/bitsquare/trade/protocol/offerer/SendSignedPayoutTx.java
@@ -1,12 +1,12 @@
 package io.bitsquare.trade.protocol.offerer;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.ECKey;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.msg.MessageFacade;
 import io.bitsquare.msg.listeners.OutgoingTradeMessageListener;
 import io.bitsquare.trade.protocol.FaultHandler;
 import io.bitsquare.trade.protocol.ResultHandler;
-import java.math.BigInteger;
 import javafx.util.Pair;
 import net.tomp2p.peers.PeerAddress;
 import org.slf4j.Logger;
@@ -25,14 +25,14 @@ public class SendSignedPayoutTx
                            String takerPayoutAddress,
                            String offererPayoutAddress,
                            String depositTransactionId,
-                           BigInteger collateral,
-                           BigInteger tradeAmount)
+                           Coin collateral,
+                           Coin tradeAmount)
     {
         log.trace("Run task");
         try
         {
-            BigInteger offererPaybackAmount = tradeAmount.add(collateral);
-            BigInteger takerPaybackAmount = collateral;
+            Coin offererPaybackAmount = tradeAmount.add(collateral);
+            Coin takerPaybackAmount = collateral;
 
             Pair<ECKey.ECDSASignature, String> result = walletFacade.offererCreatesAndSignsPayoutTx(depositTransactionId, offererPaybackAmount, takerPaybackAmount, takerPayoutAddress, tradeId);
 
diff --git a/src/main/java/io/bitsquare/trade/protocol/offerer/VerifyAndSignContract.java b/src/main/java/io/bitsquare/trade/protocol/offerer/VerifyAndSignContract.java
index 11d5c6c022..f866e79fca 100644
--- a/src/main/java/io/bitsquare/trade/protocol/offerer/VerifyAndSignContract.java
+++ b/src/main/java/io/bitsquare/trade/protocol/offerer/VerifyAndSignContract.java
@@ -1,5 +1,6 @@
 package io.bitsquare.trade.protocol.offerer;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.ECKey;
 import io.bitsquare.bank.BankAccount;
 import io.bitsquare.crypto.CryptoFacade;
@@ -7,7 +8,6 @@ import io.bitsquare.trade.Contract;
 import io.bitsquare.trade.Offer;
 import io.bitsquare.trade.protocol.FaultHandler;
 import io.bitsquare.util.Utilities;
-import java.math.BigInteger;
 import java.security.PublicKey;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -20,7 +20,7 @@ public class VerifyAndSignContract
                            FaultHandler faultHandler,
                            CryptoFacade cryptoFacade,
                            String accountId,
-                           BigInteger tradeAmount,
+                           Coin tradeAmount,
                            String takeOfferFeeTxId,
                            PublicKey messagePublicKey,
                            Offer offer,
diff --git a/src/main/java/io/bitsquare/trade/protocol/taker/CreateAndSignContract.java b/src/main/java/io/bitsquare/trade/protocol/taker/CreateAndSignContract.java
index cb713030ba..983cd2055c 100644
--- a/src/main/java/io/bitsquare/trade/protocol/taker/CreateAndSignContract.java
+++ b/src/main/java/io/bitsquare/trade/protocol/taker/CreateAndSignContract.java
@@ -1,5 +1,6 @@
 package io.bitsquare.trade.protocol.taker;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.ECKey;
 import io.bitsquare.bank.BankAccount;
 import io.bitsquare.crypto.CryptoFacade;
@@ -7,7 +8,6 @@ import io.bitsquare.trade.Contract;
 import io.bitsquare.trade.Offer;
 import io.bitsquare.trade.protocol.FaultHandler;
 import io.bitsquare.util.Utilities;
-import java.math.BigInteger;
 import java.security.PublicKey;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -20,7 +20,7 @@ public class CreateAndSignContract
                            FaultHandler faultHandler,
                            CryptoFacade cryptoFacade,
                            Offer offer,
-                           BigInteger tradeAmount,
+                           Coin tradeAmount,
                            String takeOfferFeeTxId,
                            String accountId,
                            BankAccount bankAccount,
@@ -36,7 +36,9 @@ public class CreateAndSignContract
             Contract contract = new Contract(offer, tradeAmount, takeOfferFeeTxId, peersAccountId, accountId, peersBankAccount, bankAccount, peersMessagePublicKey, messagePublicKey);
 
             String contractAsJson = Utilities.objectToJson(contract);
-            String signature = cryptoFacade.signContract(registrationKey, contractAsJson);
+            //TODO priv key is null, use other signing key or find out why it is null at that moment
+            // String signature = cryptoFacade.signContract(registrationKey, contractAsJson);
+            String signature = "TODO priv key is null, use other signing key or find out why it is null at that moment";
             resultHandler.onResult(contract, contractAsJson, signature);
         } catch (Throwable t)
         {
diff --git a/src/main/java/io/bitsquare/trade/protocol/taker/PayDeposit.java b/src/main/java/io/bitsquare/trade/protocol/taker/PayDeposit.java
index 29f4efb512..ad6f7e92a2 100644
--- a/src/main/java/io/bitsquare/trade/protocol/taker/PayDeposit.java
+++ b/src/main/java/io/bitsquare/trade/protocol/taker/PayDeposit.java
@@ -1,10 +1,10 @@
 package io.bitsquare.trade.protocol.taker;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.InsufficientMoneyException;
 import com.google.bitcoin.core.Transaction;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.trade.protocol.FaultHandler;
-import java.math.BigInteger;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -15,8 +15,8 @@ public class PayDeposit
     public static void run(ResultHandler resultHandler,
                            FaultHandler faultHandler,
                            WalletFacade walletFacade,
-                           BigInteger collateral,
-                           BigInteger tradeAmount,
+                           Coin collateral,
+                           Coin tradeAmount,
                            String tradeId,
                            String pubKeyForThatTrade,
                            String arbitratorPubKey,
@@ -26,8 +26,8 @@ public class PayDeposit
         log.trace("Run task");
         try
         {
-            BigInteger amountToPay = tradeAmount.add(collateral);
-            BigInteger msOutputAmount = amountToPay.add(collateral);
+            Coin amountToPay = tradeAmount.add(collateral);
+            Coin msOutputAmount = amountToPay.add(collateral);
 
             Transaction signedTakerDepositTx = walletFacade.takerAddPaymentAndSignTx(amountToPay,
                                                                                      msOutputAmount,
diff --git a/src/main/java/io/bitsquare/trade/protocol/taker/ProtocolForTakerAsSeller.java b/src/main/java/io/bitsquare/trade/protocol/taker/ProtocolForTakerAsSeller.java
index 28fc32c346..2eb5946955 100644
--- a/src/main/java/io/bitsquare/trade/protocol/taker/ProtocolForTakerAsSeller.java
+++ b/src/main/java/io/bitsquare/trade/protocol/taker/ProtocolForTakerAsSeller.java
@@ -1,5 +1,6 @@
 package io.bitsquare.trade.protocol.taker;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.ECKey;
 import com.google.bitcoin.core.Transaction;
 import io.bitsquare.bank.BankAccount;
@@ -15,7 +16,6 @@ import io.bitsquare.trade.protocol.offerer.DepositTxPublishedMessage;
 import io.bitsquare.trade.protocol.offerer.RequestTakerDepositPaymentMessage;
 import io.bitsquare.trade.protocol.offerer.RespondToTakeOfferRequestMessage;
 import io.bitsquare.user.User;
-import java.math.BigInteger;
 import java.security.PublicKey;
 import net.tomp2p.peers.PeerAddress;
 import org.slf4j.Logger;
@@ -68,11 +68,11 @@ public class ProtocolForTakerAsSeller
     private final BankAccount bankAccount;
     private final String accountId;
     private final PublicKey messagePublicKey;
-    private final BigInteger tradeAmount;
+    private final Coin tradeAmount;
     private final String pubKeyForThatTrade;
     private final ECKey accountKey;
     private final PublicKey peersMessagePublicKey;
-    private final BigInteger collateral;
+    private final Coin collateral;
     private final String arbitratorPubKey;
 
     // written/read by task
@@ -88,8 +88,8 @@ public class ProtocolForTakerAsSeller
     private String depositTxAsHex;
     private String offererSignatureR;
     private String offererSignatureS;
-    private BigInteger offererPaybackAmount;
-    private BigInteger takerPaybackAmount;
+    private Coin offererPaybackAmount;
+    private Coin takerPaybackAmount;
     private String offererPayoutAddress;
 
 
@@ -319,8 +319,8 @@ public class ProtocolForTakerAsSeller
         String depositTxAsHex = nonEmptyStringOf(message.getDepositTxAsHex());
         String offererSignatureR = nonEmptyStringOf(message.getOffererSignatureR());
         String offererSignatureS = nonEmptyStringOf(message.getOffererSignatureS());
-        BigInteger offererPaybackAmount = nonNegativeBigIntegerOf(nonZeroBigIntegerOf(message.getOffererPaybackAmount()));
-        BigInteger takerPaybackAmount = nonNegativeBigIntegerOf(nonZeroBigIntegerOf(message.getTakerPaybackAmount()));
+        Coin offererPaybackAmount = positiveCoinOf(nonZeroCoinOf(message.getOffererPaybackAmount()));
+        Coin takerPaybackAmount = positiveCoinOf(nonZeroCoinOf(message.getTakerPaybackAmount()));
         String offererPayoutAddress = nonEmptyStringOf(message.getOffererPayoutAddress());
 
         // apply state
diff --git a/src/main/java/io/bitsquare/trade/protocol/taker/SendSignedTakerDepositTxAsHex.java b/src/main/java/io/bitsquare/trade/protocol/taker/SendSignedTakerDepositTxAsHex.java
index 47cfda2eb5..487075822e 100644
--- a/src/main/java/io/bitsquare/trade/protocol/taker/SendSignedTakerDepositTxAsHex.java
+++ b/src/main/java/io/bitsquare/trade/protocol/taker/SendSignedTakerDepositTxAsHex.java
@@ -38,12 +38,12 @@ public class SendSignedTakerDepositTxAsHex
                                                                                                        bankAccount,
                                                                                                        accountId,
                                                                                                        messagePublicKey,
-                                                                                                       Utils.bytesToHexString(signedTakerDepositTx.bitcoinSerialize()),
-                                                                                                       Utils.bytesToHexString(signedTakerDepositTx.getInput(1).getScriptBytes()),
-                                                                                                       Utils.bytesToHexString(signedTakerDepositTx.getInput(1)
-                                                                                                                                                  .getConnectedOutput()
-                                                                                                                                                  .getParentTransaction()
-                                                                                                                                                  .bitcoinSerialize()),
+                                                                                                       Utils.HEX.encode(signedTakerDepositTx.bitcoinSerialize()),
+                                                                                                       Utils.HEX.encode(signedTakerDepositTx.getInput(1).getScriptBytes()),
+                                                                                                       Utils.HEX.encode(signedTakerDepositTx.getInput(1)
+                                                                                                                                            .getConnectedOutput()
+                                                                                                                                            .getParentTransaction()
+                                                                                                                                            .bitcoinSerialize()),
                                                                                                        contractAsJson,
                                                                                                        takerSignature,
                                                                                                        walletFacade.getAddressInfoByTradeID(tradeId).getAddressString(),
diff --git a/src/main/java/io/bitsquare/trade/protocol/taker/SendTakeOfferFeePayedTxId.java b/src/main/java/io/bitsquare/trade/protocol/taker/SendTakeOfferFeePayedTxId.java
index 508482d346..7146103614 100644
--- a/src/main/java/io/bitsquare/trade/protocol/taker/SendTakeOfferFeePayedTxId.java
+++ b/src/main/java/io/bitsquare/trade/protocol/taker/SendTakeOfferFeePayedTxId.java
@@ -1,10 +1,10 @@
 package io.bitsquare.trade.protocol.taker;
 
+import com.google.bitcoin.core.Coin;
 import io.bitsquare.msg.MessageFacade;
 import io.bitsquare.msg.listeners.OutgoingTradeMessageListener;
 import io.bitsquare.trade.protocol.FaultHandler;
 import io.bitsquare.trade.protocol.ResultHandler;
-import java.math.BigInteger;
 import net.tomp2p.peers.PeerAddress;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -19,7 +19,7 @@ public class SendTakeOfferFeePayedTxId
                            MessageFacade messageFacade,
                            String tradeId,
                            String takeOfferFeeTxId,
-                           BigInteger tradeAmount,
+                           Coin tradeAmount,
                            String pubKeyForThatTradeAsHex)
     {
         log.trace("Run task");
diff --git a/src/main/java/io/bitsquare/trade/protocol/taker/SignAndPublishPayoutTx.java b/src/main/java/io/bitsquare/trade/protocol/taker/SignAndPublishPayoutTx.java
index c0ffc61516..8f705df664 100644
--- a/src/main/java/io/bitsquare/trade/protocol/taker/SignAndPublishPayoutTx.java
+++ b/src/main/java/io/bitsquare/trade/protocol/taker/SignAndPublishPayoutTx.java
@@ -1,11 +1,11 @@
 package io.bitsquare.trade.protocol.taker;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.Transaction;
 import com.google.bitcoin.core.Utils;
 import com.google.common.util.concurrent.FutureCallback;
 import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.trade.protocol.FaultHandler;
-import java.math.BigInteger;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -20,8 +20,8 @@ public class SignAndPublishPayoutTx
                            String depositTxAsHex,
                            String offererSignatureR,
                            String offererSignatureS,
-                           BigInteger offererPaybackAmount,
-                           BigInteger takerPaybackAmount,
+                           Coin offererPaybackAmount,
+                           Coin takerPaybackAmount,
                            String offererPayoutAddress)
     {
         log.trace("Run task");
@@ -41,7 +41,7 @@ public class SignAndPublishPayoutTx
                                                   public void onSuccess(Transaction transaction)
                                                   {
                                                       log.debug("takerSignsAndSendsTx " + transaction);
-                                                      String payoutTxAsHex = Utils.bytesToHexString(transaction.bitcoinSerialize());
+                                                      String payoutTxAsHex = Utils.HEX.encode(transaction.bitcoinSerialize());
                                                       resultHandler.onResult(transaction.getHashAsString(), payoutTxAsHex);
                                                   }
 
diff --git a/src/main/java/io/bitsquare/trade/protocol/taker/TakeOfferFeePayedMessage.java b/src/main/java/io/bitsquare/trade/protocol/taker/TakeOfferFeePayedMessage.java
index 28a6f19524..02da8a0532 100644
--- a/src/main/java/io/bitsquare/trade/protocol/taker/TakeOfferFeePayedMessage.java
+++ b/src/main/java/io/bitsquare/trade/protocol/taker/TakeOfferFeePayedMessage.java
@@ -1,19 +1,19 @@
 package io.bitsquare.trade.protocol.taker;
 
+import com.google.bitcoin.core.Coin;
 import io.bitsquare.trade.protocol.TradeMessage;
 import java.io.Serializable;
-import java.math.BigInteger;
 
 public class TakeOfferFeePayedMessage implements Serializable, TradeMessage
 {
     private static final long serialVersionUID = -5057935061275354312L;
     private final String tradeId;
 
-    private BigInteger tradeAmount;
+    private Coin tradeAmount;
     private String takeOfferFeeTxID;
     private String takerPubKey;
 
-    public TakeOfferFeePayedMessage(String tradeId, String takeOfferFeeTxID, BigInteger tradeAmount, String takerPubKey)
+    public TakeOfferFeePayedMessage(String tradeId, String takeOfferFeeTxID, Coin tradeAmount, String takerPubKey)
     {
         this.tradeId = tradeId;
         this.takeOfferFeeTxID = takeOfferFeeTxID;
@@ -27,7 +27,7 @@ public class TakeOfferFeePayedMessage implements Serializable, TradeMessage
         return tradeId;
     }
 
-    public BigInteger getTradeAmount()
+    public Coin getTradeAmount()
     {
         return tradeAmount;
     }
diff --git a/src/main/java/io/bitsquare/util/DSAKeyUtil.java b/src/main/java/io/bitsquare/util/DSAKeyUtil.java
index 824c2a3d1d..e2c8657245 100755
--- a/src/main/java/io/bitsquare/util/DSAKeyUtil.java
+++ b/src/main/java/io/bitsquare/util/DSAKeyUtil.java
@@ -22,7 +22,7 @@ public class DSAKeyUtil
     public static String getHexStringFromPublicKey(PublicKey publicKey)
     {
         final X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(publicKey.getEncoded());
-        return Utils.bytesToHexString(x509EncodedKeySpec.getEncoded());
+        return Utils.HEX.encode(x509EncodedKeySpec.getEncoded());
     }
 
     public static KeyPair generateKeyPair()
diff --git a/src/main/java/io/bitsquare/util/Utilities.java b/src/main/java/io/bitsquare/util/Utilities.java
index 230b75ba84..d8a5ad6cae 100644
--- a/src/main/java/io/bitsquare/util/Utilities.java
+++ b/src/main/java/io/bitsquare/util/Utilities.java
@@ -66,7 +66,7 @@ public class Utilities
             ObjectOutputStream objectOutputStream = new ObjectOutputStream(byteArrayOutputStream);
             objectOutputStream.writeObject(serializable);
 
-            result = com.google.bitcoin.core.Utils.bytesToHexString(byteArrayOutputStream.toByteArray());
+            result = com.google.bitcoin.core.Utils.HEX.encode(byteArrayOutputStream.toByteArray());
             byteArrayOutputStream.close();
             objectOutputStream.close();
 
diff --git a/src/main/java/io/bitsquare/util/Validator.java b/src/main/java/io/bitsquare/util/Validator.java
index 03224c9778..0e2357d3b0 100644
--- a/src/main/java/io/bitsquare/util/Validator.java
+++ b/src/main/java/io/bitsquare/util/Validator.java
@@ -1,6 +1,6 @@
 package io.bitsquare.util;
 
-import java.math.BigInteger;
+import com.google.bitcoin.core.Coin;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -24,17 +24,17 @@ public class Validator
         return value;
     }
 
-    public static BigInteger nonZeroBigIntegerOf(BigInteger value)
+    public static Coin nonZeroCoinOf(Coin value)
     {
         checkNotNull(value);
-        checkArgument(value.compareTo(BigInteger.ZERO) != 0);
+        checkArgument(!value.isZero());
         return value;
     }
 
-    public static BigInteger nonNegativeBigIntegerOf(BigInteger value)
+    public static Coin positiveCoinOf(Coin value)
     {
         checkNotNull(value);
-        checkArgument(value.compareTo(BigInteger.ZERO) >= 0);
+        checkArgument(value.isPositive());
         return value;
     }
 
diff --git a/src/main/resources/logback.xml b/src/main/resources/logback.xml
index 20a0502932..4fe624609c 100644
--- a/src/main/resources/logback.xml
+++ b/src/main/resources/logback.xml
@@ -26,7 +26,7 @@
     <logger name="com.google.bitcoin" level="WARN"/>
 
 
-    <logger name="net.tomp2p" level="WARN"/>
+    <logger name="net.tomp2p" level="DEBUG"/>
 
     <logger name="io.netty.util" level="WARN"/>
     <logger name="io.netty.channel" level="WARN"/>
diff --git a/src/test/java/io/bitsquare/btc/BtcValidatorTest.java b/src/test/java/io/bitsquare/btc/BtcValidatorTest.java
index 3c800da90f..d3b5eb3754 100644
--- a/src/test/java/io/bitsquare/btc/BtcValidatorTest.java
+++ b/src/test/java/io/bitsquare/btc/BtcValidatorTest.java
@@ -1,7 +1,7 @@
 package io.bitsquare.btc;
 
+import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.Transaction;
-import java.math.BigInteger;
 import org.junit.Test;
 
 import static org.junit.Assert.assertFalse;
@@ -12,11 +12,11 @@ public class BtcValidatorTest
     @Test
     public void testIsMinSpendableAmount()
     {
-        BigInteger amount = null;
+        Coin amount = null;
         //noinspection ConstantConditions
         assertFalse("tx unfunded, pending", BtcValidator.isMinSpendableAmount(amount));
 
-        amount = BigInteger.ZERO;
+        amount = Coin.ZERO;
         assertFalse("tx unfunded, pending", BtcValidator.isMinSpendableAmount(amount));
 
         amount = FeePolicy.TX_FEE;
@@ -28,7 +28,7 @@ public class BtcValidatorTest
         amount = FeePolicy.TX_FEE.add(Transaction.MIN_NONDUST_OUTPUT);
         assertFalse("tx unfunded, pending", BtcValidator.isMinSpendableAmount(amount));
 
-        amount = FeePolicy.TX_FEE.add(Transaction.MIN_NONDUST_OUTPUT).add(BigInteger.ONE);
+        amount = FeePolicy.TX_FEE.add(Transaction.MIN_NONDUST_OUTPUT).add(Coin.valueOf(1));
         assertTrue("tx unfunded, pending", BtcValidator.isMinSpendableAmount(amount));
     }
 }