From 501530d85f3e2fae98a18a766a6bfda4a99fc645 Mon Sep 17 00:00:00 2001
From: woodser <13068859+woodser@users.noreply.github.com>
Date: Mon, 2 Jun 2025 08:48:03 -0400
Subject: [PATCH] read bip39 words once and synchronized

---
 .../java/haveno/core/trade/HavenoUtils.java   | 21 ++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/core/src/main/java/haveno/core/trade/HavenoUtils.java b/core/src/main/java/haveno/core/trade/HavenoUtils.java
index 74caf5d7f2..32a6d76824 100644
--- a/core/src/main/java/haveno/core/trade/HavenoUtils.java
+++ b/core/src/main/java/haveno/core/trade/HavenoUtils.java
@@ -123,6 +123,7 @@ public class HavenoUtils {
     private static final BigInteger XMR_AU_MULTIPLIER = new BigInteger("1000000000000");
     public static final DecimalFormat XMR_FORMATTER = new DecimalFormat("##############0.000000000000", DECIMAL_FORMAT_SYMBOLS);
     public static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
+    private static List<String> bip39Words = new ArrayList<String>();
 
     // shared references TODO: better way to share references?
     public static HavenoSetup havenoSetup;
@@ -298,10 +299,7 @@ public class HavenoUtils {
         try {
 
             // load bip39 words
-            String fileName = "bip39_english.txt";
-            File bip39File = new File(havenoSetup.getConfig().appDataDir, fileName);
-            if (!bip39File.exists()) FileUtil.resourceToFile(fileName, bip39File);
-            List<String> bip39Words = Files.readAllLines(bip39File.toPath(), StandardCharsets.UTF_8);
+            loadBip39Words();
 
             // select words randomly
             List<String> passphraseWords = new ArrayList<String>();
@@ -315,13 +313,26 @@ public class HavenoUtils {
         }
     }
 
+    private static synchronized void loadBip39Words() {
+        if (bip39Words.isEmpty()) {
+            try {
+                String fileName = "bip39_english.txt";
+                File bip39File = new File(havenoSetup.getConfig().appDataDir, fileName);
+                if (!bip39File.exists()) FileUtil.resourceToFile(fileName, bip39File);
+                bip39Words = Files.readAllLines(bip39File.toPath(), StandardCharsets.UTF_8);
+            } catch (Exception e) {
+                throw new IllegalStateException("Failed to load BIP39 words", e);
+            }
+        }
+    }
+
     public static String getChallengeHash(String challenge) {
         if (challenge == null) return null;
 
         // tokenize passphrase
         String[] words = challenge.toLowerCase().split(" ");
 
-        // collect first 4 letters of each word, which are unique in bip39
+        // collect up to first 4 letters of each word, which are unique in bip39
         List<String> prefixes = new ArrayList<String>();
         for (String word : words) prefixes.add(word.substring(0, Math.min(word.length(), 4)));