tornado-core/circuits/withdraw.circom
2019-07-10 15:35:46 +03:00

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include "../node_modules/circomlib/circuits/bitify.circom";
include "../node_modules/circomlib/circuits/pedersen.circom";
include "merkleTree.circom";
// computes Pedersen(nullifier + secret)
template CommitmentHasher() {
signal input nullifier;
signal private input secret;
signal output hash;
component commitment = Pedersen(512);
component nullifierBits = Num2Bits(256);
component secretBits = Num2Bits(256);
nullifierBits.in <== nullifier;
secretBits.in <== secret;
for (var i = 0; i < 256; i++) {
commitment.in[i] <== nullifierBits.out[i];
commitment.in[i + 256] <== secretBits.out[i];
}
hash <== commitment.out[0];
}
// Verifies that commitment that corresponds to given secret and nullifier is included in the merkle tree of deposits
template Withdraw(levels, rounds) {
signal input root;
signal input nullifier;
signal input receiver; // not taking part in any computations
signal input fee; // not taking part in any computations
signal private input secret;
signal private input pathElements[levels];
signal private input pathIndex[levels];
component hasher = CommitmentHasher();
hasher.nullifier <== nullifier;
hasher.secret <== secret;
component tree = MerkleTree(levels, rounds);
tree.leaf <== hasher.hash;
tree.root <== root;
for (var i = 0; i < levels; i++) {
tree.pathElements[i] <== pathElements[i];
tree.pathIndex[i] <== pathIndex[i];
}
// TODO: Check if we need some kind of explicit constraints or something
fee === fee;
receiver === receiver;
}
component main = Withdraw(16, 220);