Merge pull request #1700 from privacy-scaling-explorations/chore/cont…

…racts-optimisations-mp

chore: optimize message processor and tally

.eslintrc.js

@@ -59,7 +59,7 @@ module.exports = {
     "import/no-extraneous-dependencies": [
       "error",
       {
-        devDependencies: ["**/*.test.ts", "**/__benchmarks__/**"],
+        devDependencies: ["**/*.test.ts", "**/__benchmarks__/**", "**/tests/**", "**/__tests__/**"],
       },
     ],
     "no-debugger": isProduction ? "error" : "off",

.github/workflows/reusable-e2e.yml

@@ -61,12 +61,6 @@ jobs:
         run: |
           pnpm run build
 
-      - name: Run hardhat fork
-        run: |
-          cd contracts
-          pnpm run hardhat &
-          sleep 5
-
       - name: Download rapidsnark (1c137)
         run: |
           mkdir -p ~/rapidsnark/build
@@ -90,6 +84,12 @@ jobs:
         run: |
           pnpm download-zkeys:test
 
+      - name: Run hardhat fork
+        run: |
+          pnpm run hardhat &
+          sleep 5
+        working-directory: contracts
+
       - name: ${{ matrix.command }}
         run: pnpm run ${{ matrix.command }}
 

circuits/.gitignore

@@ -2,3 +2,5 @@ ptau
 input.json
 circom/main
 circom/test
+zkeys/
+

circuits/circom/circuits.json

@@ -3,24 +3,42 @@
     "file": "./core/qv/processMessages",
     "template": "ProcessMessages",
     "params": [10, 2, 1, 2],
-    "pubs": ["inputHash"]
+    "pubs": [
+      "numSignUps",
+      "index",
+      "batchEndIndex",
+      "msgRoot",
+      "currentSbCommitment",
+      "newSbCommitment",
+      "pollEndTimestamp",
+      "actualStateTreeDepth"
+    ]
   },
   "ProcessMessagesNonQv_10-2-1-2_test": {
     "file": "./core/non-qv/processMessages",
     "template": "ProcessMessagesNonQv",
     "params": [10, 2, 1, 2],
-    "pubs": ["inputHash"]
+    "pubs": [
+      "numSignUps",
+      "index",
+      "batchEndIndex",
+      "msgRoot",
+      "currentSbCommitment",
+      "newSbCommitment",
+      "pollEndTimestamp",
+      "actualStateTreeDepth"
+    ]
   },
   "TallyVotes_10-1-2_test": {
     "file": "./core/qv/tallyVotes",
     "template": "TallyVotes",
     "params": [10, 1, 2],
-    "pubs": ["inputHash"]
+    "pubs": ["index", "numSignUps", "sbCommitment", "currentTallyCommitment", "newTallyCommitment"]
   },
   "TallyVotesNonQv_10-1-2_test": {
     "file": "./core/non-qv/tallyVotes",
     "template": "TallyVotesNonQv",
     "params": [10, 1, 2],
-    "pubs": ["inputHash"]
+    "pubs": ["index", "numSignUps", "sbCommitment", "currentTallyCommitment", "newTallyCommitment"]
   }
 }

circuits/circom/core/non-qv/processMessages.circom

@@ -8,7 +8,6 @@ include "./safe-comparators.circom";
 include "../../utils/hashers.circom";
 include "../../utils/messageToCommand.circom";
 include "../../utils/privToPubKey.circom";
-include "../../utils/processMessagesInputHasher.circom";
 include "../../utils/non-qv/stateLeafAndBallotTransformer.circom";
 include "../../trees/incrementalMerkleTree.circom";
 include "../../trees/incrementalQuinaryTree.circom";
@@ -36,6 +35,7 @@ include "../../trees/incrementalQuinaryTree.circom";
     // Default for Binary trees.
     var STATE_TREE_ARITY = 2;
     var batchSize = MESSAGE_TREE_ARITY ** msgBatchDepth;
+    var maxVoteOptions = MESSAGE_TREE_ARITY ** voteOptionTreeDepth;
     var MSG_LENGTH = 10;
     var PACKED_CMD_LENGTH = 4;
     var STATE_LEAF_LENGTH = 4;
@@ -48,17 +48,8 @@ include "../../trees/incrementalQuinaryTree.circom";
     var STATE_LEAF_TIMESTAMP_IDX = 3;
     var msgTreeZeroValue = 8370432830353022751713833565135785980866757267633941821328460903436894336785;
 
-    // nb. The usage of SHA-256 hash is necessary to save some gas costs at verification time
-    // at the cost of more constraints for the prover.
-    // Basically, some values from the contract are passed as private inputs and the hash as a public input.
-
-    // The SHA-256 hash of values provided by the contract.
-    signal input inputHash;
-    signal input packedVals;
     // Number of users that have completed the sign up.
-    signal numSignUps;
-    // Number of options for this poll.
-    signal maxVoteOptions;
+    signal input numSignUps;
     // Time when the poll ends.
     signal input pollEndTimestamp;
     // The existing message tree root.
@@ -79,6 +70,10 @@ include "../../trees/incrementalQuinaryTree.circom";
     // @note it is a public input to ensure fair processing from 
     // the coordinator (no censoring)
     signal input actualStateTreeDepth;
+    // The last batch index
+    signal input batchEndIndex;
+    // The batch index of current message batch
+    signal input index;
 
     // The state leaves upon which messages are applied.
     //    transform(currentStateLeaf[4], message5) => newStateLeaf4
@@ -110,14 +105,6 @@ include "../../trees/incrementalQuinaryTree.circom";
     // Therefore, the index of the first message to process does not match the index of the
     // first message (e.g., [msg1, msg2, msg3] => first message to process has index 3).
 
-    // The index of the first message leaf in the batch, inclusive.
-    signal batchStartIndex;
-
-    // The index of the last message leaf in the batch to process, exclusive.
-    // This value may be less than batchStartIndex + batchSize if this batch is
-    // the last batch and the total number of messages is not a multiple of the batch size.
-    signal batchEndIndex;
-
     // The history of state and ballot roots and temporary intermediate
     // signals (for processing purposes).
     signal stateRoots[batchSize + 1];
@@ -131,31 +118,6 @@ include "../../trees/incrementalQuinaryTree.circom";
     var computedCurrentSbCommitment = PoseidonHasher(3)([currentStateRoot, currentBallotRoot, currentSbSalt]);
     computedCurrentSbCommitment === currentSbCommitment;
 
-    // Verify public inputs and assign unpacked values.
-    var (
-        computedMaxVoteOptions, 
-        computedNumSignUps, 
-        computedBatchStartIndex, 
-        computedBatchEndIndex, 
-        computedHash
-    ) = ProcessMessagesInputHasher()(
-        packedVals,
-        coordPubKey,
-        msgRoot,
-        currentSbCommitment,
-        newSbCommitment,
-        pollEndTimestamp,
-        actualStateTreeDepth
-    );
-
-    // The unpacked values from packedVals.
-    computedMaxVoteOptions ==> maxVoteOptions;
-    computedNumSignUps ==> numSignUps;
-    computedBatchStartIndex ==> batchStartIndex;
-    computedBatchEndIndex ==> batchEndIndex;
-    // Matching constraints.
-    computedHash === inputHash;
-
     //  ----------------------------------------------------------------------- 
     // 0. Ensure that the maximum vote options signal is valid and if
     // the maximum users signal is valid.
@@ -173,7 +135,7 @@ include "../../trees/incrementalQuinaryTree.circom";
         computedMessageHashers[i] = MessageHasher()(msgs[i], encPubKeys[i]);
     }
 
-    // If batchEndIndex - batchStartIndex < batchSize, the remaining
+    // If endIndex - startIndex < batchSize, the remaining
     // message hashes should be the zero value.
     // e.g. [m, z, z, z, z] if there is only 1 real message in the batch
     // This makes possible to have a batch of messages which is only partially full.
@@ -182,7 +144,7 @@ include "../../trees/incrementalQuinaryTree.circom";
     var computedPathIndex[msgTreeDepth - msgBatchDepth];
 
     for (var i = 0; i < batchSize; i++) {
-        var batchStartIndexValid = SafeLessThan(32)([batchStartIndex + i, batchEndIndex]);
+        var batchStartIndexValid = SafeLessThan(32)([index + i, batchEndIndex]);
         computedLeaves[i] = Mux1()([msgTreeZeroValue, computedMessageHashers[i]], batchStartIndexValid);
     }
 
@@ -195,8 +157,8 @@ include "../../trees/incrementalQuinaryTree.circom";
     // Computing the path_index values. Since msgBatchLeavesExists tests
     // the existence of a subroot, the length of the proof correspond to the last 
     // n elements of a proof from the root to a leaf, where n = msgTreeDepth - msgBatchDepth.
-    // e.g. if batchStartIndex = 25, msgTreeDepth = 4, msgBatchDepth = 2, then path_index = [1, 0].
-    var computedMsgBatchPathIndices[msgTreeDepth] = QuinGeneratePathIndices(msgTreeDepth)(batchStartIndex);
+    // e.g. if startIndex = 25, msgTreeDepth = 4, msgBatchDepth = 2, then path_index = [1, 0].
+    var computedMsgBatchPathIndices[msgTreeDepth] = QuinGeneratePathIndices(msgTreeDepth)(index);
 
     for (var i = msgBatchDepth; i < msgTreeDepth; i++) {
         computedPathIndex[i - msgBatchDepth] = computedMsgBatchPathIndices[i];
@@ -286,7 +248,6 @@ include "../../trees/incrementalQuinaryTree.circom";
 
         (computedNewVoteStateRoot[i], computedNewVoteBallotRoot[i]) = ProcessOneNonQv(stateTreeDepth, voteOptionTreeDepth)(
             numSignUps,
-            maxVoteOptions,
             pollEndTimestamp,
             stateRoots[i + 1],
             ballotRoots[i + 1],
@@ -336,6 +297,7 @@ template ProcessOneNonQv(stateTreeDepth, voteOptionTreeDepth) {
     var BALLOT_NONCE_IDX = 0;
     // Ballot vote option (VO) root index.
     var BALLOT_VO_ROOT_IDX = 1;
+    var maxVoteOptions = MESSAGE_TREE_ARITY ** voteOptionTreeDepth;
 
     // Indices for elements within a state leaf.
     // Public key.
@@ -348,7 +310,6 @@ template ProcessOneNonQv(stateTreeDepth, voteOptionTreeDepth) {
 
     // Inputs representing the message and the current state.
     signal input numSignUps;
-    signal input maxVoteOptions;
     signal input pollEndTimestamp;
 
     // The current value of the state tree root.

circuits/circom/core/non-qv/tallyVotes.circom

@@ -9,7 +9,6 @@ include "../../trees/incrementalMerkleTree.circom";
 include "../../trees/incrementalQuinaryTree.circom";
 include "../../utils/calculateTotal.circom";
 include "../../utils/hashers.circom";
-include "../../utils/tallyVotesInputHasher.circom";
 
 /**
  * Processes batches of votes and verifies their validity in a Merkle tree structure.
@@ -51,70 +50,40 @@ template TallyVotesNonQv(
     signal input ballotRoot;
     // Salt used in commitment to secure the ballot data.
     signal input sbSalt;
-
-    // Inputs combined into a hash to verify the integrity and authenticity of the data.
-    signal input packedVals;
     // Commitment to the state and ballots.
     signal input sbCommitment;
     // Commitment to the current tally before this batch.
     signal input currentTallyCommitment;
     // Commitment to the new tally after processing this batch.
     signal input newTallyCommitment;
-
-    // A tally commitment is the hash of the following salted values:
-    //   - the vote results,
-    //   - the number of voice credits spent per vote option,
-    //   - the total number of spent voice credits.
-
-    // Hash of all inputs to ensure they are unchanged and authentic.
-    signal input inputHash;
-
+    // Start index of given batch
+    signal input index;
+    // Number of users that signup
+    signal input numSignUps;
     // Ballots and their corresponding path elements for verification in the tree.
     signal input ballots[batchSize][BALLOT_LENGTH];
     signal input ballotPathElements[k][BALLOT_TREE_ARITY - 1];
     signal input votes[batchSize][numVoteOptions];
-
     // Current results for each vote option.
     signal input currentResults[numVoteOptions];
     // Salt for the root of the current results.
     signal input currentResultsRootSalt;
-
     // Total voice credits spent so far.
     signal input currentSpentVoiceCreditSubtotal;
     // Salt for the total spent voice credits.
     signal input currentSpentVoiceCreditSubtotalSalt;
-
     // Salt for the root of the new results.
     signal input newResultsRootSalt;
     // Salt for the new total spent voice credits root. 
     signal input newSpentVoiceCreditSubtotalSalt;
-    // The number of total registrations, used to validate the batch index.
-    signal numSignUps;
-    // Index of the first ballot in this batch.
-    signal batchStartIndex;
 
     // Verify sbCommitment.
     var computedSbCommitment = PoseidonHasher(3)([stateRoot, ballotRoot, sbSalt]);
     computedSbCommitment === sbCommitment;
 
-    // Verify inputHash.
-    var (
-        computedNumSignUps,
-        computedBatchNum,
-        computedHash
-    ) = TallyVotesInputHasher()(
-        sbCommitment,
-        currentTallyCommitment,
-        newTallyCommitment,
-        packedVals
-    );
-
-    inputHash === computedHash;
-    numSignUps <== computedNumSignUps;
-    batchStartIndex <== computedBatchNum * batchSize;
 
-    // Validates that the batchStartIndex is within the valid range of sign-ups.
-    var numSignUpsValid = LessEqThan(50)([batchStartIndex, numSignUps]);
+    // Validates that the index is within the valid range of sign-ups.
+    var numSignUpsValid = LessEqThan(50)([index, numSignUps]);
     numSignUpsValid === 1;
 
     // Hashes each ballot for subroot generation, and checks the existence of the leaf in the Merkle tree.    
@@ -125,7 +94,7 @@ template TallyVotesNonQv(
     }
 
     var computedBallotSubroot = CheckRoot(intStateTreeDepth)(computedBallotHashers);
-    var computedBallotPathIndices[k] = MerkleGeneratePathIndices(k)(computedBatchNum);
+    var computedBallotPathIndices[k] = MerkleGeneratePathIndices(k)(index / batchSize);
 
     // Verifies each ballot's existence within the ballot tree.
     LeafExists(k)(
@@ -143,7 +112,7 @@ template TallyVotesNonQv(
     }
 
     // Calculates new results and spent voice credits based on the current and incoming votes.
-    var computedIsFirstBatch = IsZero()(batchStartIndex);
+    var computedIsFirstBatch = IsZero()(index);
     var computedIsZero = IsZero()(computedIsFirstBatch);
 
     // Tally the new results.