Merge pull request #282 from corydickson/first-batch-vo

Add is zero to initial vote tally credits
privacy-scaling-explorations · Sep 20, 2021 · 4892ada · 4892ada
2 parents 4bc217d + 61d45ed
commit 4892ada
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Showing 2 changed files with 12 additions and 2 deletions.
diff --git a/circuits/circom/tallyVotes.circom b/circuits/circom/tallyVotes.circom
@@ -151,7 +151,7 @@ template TallyVotes(
 
     // Tally the new total of spent voice credits
     component newSpentVoiceCreditSubtotal = CalculateTotal(batchSize * numVoteOptions + 1);
-    newSpentVoiceCreditSubtotal.nums[batchSize * numVoteOptions] <== currentSpentVoiceCreditSubtotal;
+    newSpentVoiceCreditSubtotal.nums[batchSize * numVoteOptions] <== currentSpentVoiceCreditSubtotal * iz.out;
     for (var i = 0; i < batchSize; i ++) {
         for (var j = 0; j < numVoteOptions; j ++) {
             newSpentVoiceCreditSubtotal.nums[i * numVoteOptions + j] <==
@@ -163,7 +163,7 @@ template TallyVotes(
     component newPerVOSpentVoiceCredits[numVoteOptions];
     for (var i = 0; i < numVoteOptions; i ++) {
         newPerVOSpentVoiceCredits[i] = CalculateTotal(batchSize + 1);
-        newPerVOSpentVoiceCredits[i].nums[batchSize] <== currentPerVOSpentVoiceCredits[i];
+        newPerVOSpentVoiceCredits[i].nums[batchSize] <== currentPerVOSpentVoiceCredits[i] * iz.out;
         for (var j = 0; j < batchSize; j ++) {
             newPerVOSpentVoiceCredits[i].nums[j] <== votes[j][i] * votes[j][i];
         }

diff --git a/circuits/ts/__tests__/TallyVotes.test.ts b/circuits/ts/__tests__/TallyVotes.test.ts
@@ -224,6 +224,16 @@ describe('TallyVotes circuit', () => {
 
             for (let i = 0; i < NUM_BATCHES; i ++) {
                 const generatedInputs = poll.tallyVotes()
+
+                // For the 0th batch, the circuit should ignore currentResults,
+                // currentSpentVoiceCreditSubtotal, and
+                // currentPerVOSpentVoiceCredits
+                if (i === 0) {
+                    generatedInputs.currentResults[0] = '123'
+                    generatedInputs.currentSpentVoiceCreditSubtotal = '456'
+                    generatedInputs.currentPerVOSpentVoiceCredits[0] = '789'
+                }
+
                 const witness = await genWitness(circuit, generatedInputs)
                 expect(witness.length > 0).toBeTruthy()
             }