feat(zk-snarks): AG-32 defined voting program (#39)

defined municipality election voting zk-snarks protocol

contracts/MunicipalityElection.sol

@@ -11,7 +11,6 @@ contract MunicipalityElection is Election {
     struct Candidate {
         string name;
         string candidatesFor; // major or councilor
-        uint256 points;
     }
 
     /// @dev the string key of the map correspond tho the party name registered in the parties mapping
@@ -112,8 +111,7 @@ contract MunicipalityElection is Election {
 
             Candidate memory c = Candidate({
                 name: councilorCandidates[i],
-                candidatesFor: "councilor",
-                points: 0
+                candidatesFor: "councilor"
             });
 
             candidatesList.push(c);
@@ -143,8 +141,7 @@ contract MunicipalityElection is Election {
 
         Candidate memory mcandidate = Candidate({
             name: majorCandidate,
-            candidatesFor: "major",
-            points: 0
+            candidatesFor: "major"
         });
 
         Coalition memory newCoalition;

election-scripts/__mocks__.ts

@@ -40,6 +40,7 @@ export const MAJOR_CANDIDATE_2 = "Ugo Silenti";
 export const PARTIES: Party[] = [
   {
     name: PARTY_NAME_A,
+    points: 0,
     councilorCandidates: [
       "Luigi Rossi",
       "Maria Verdi",
@@ -50,6 +51,7 @@ export const PARTIES: Party[] = [
   },
   {
     name: PARTY_NAME_B,
+    points: 0,
     councilorCandidates: [
       "Francesca Riti",
       "Vanessa Reti",
@@ -60,6 +62,7 @@ export const PARTIES: Party[] = [
   },
   {
     name: PARTY_NAME_C,
+    points: 0,
     councilorCandidates: [
       "Giuseppe Toni",
       "Nicolò Movizzo",
@@ -70,6 +73,7 @@ export const PARTIES: Party[] = [
   },
   {
     name: PARTY_NAME_D,
+    points: 0,
     councilorCandidates: [
       "Patrizio Pini",
       "Mariagrazia Crudi",

election-scripts/create-election.test.ts

@@ -42,9 +42,6 @@ describe("Create Election Script", () => {
       expect(coalitionFromContract[0][1]).to.equal(
         coalition.majorCandidate.candidatesFor,
       );
-      expect(coalitionFromContract[0][2]).to.equal(
-        coalition.majorCandidate.points,
-      );
       expect(coalitionFromContract[1]).to.deep.equal(
         coalition.parties.map((p) => p.name),
       );

election-scripts/create-election.ts

@@ -92,14 +92,15 @@ export async function main(
       majorCandidate: {
         name: coalition1Raw[0][0],
         candidatesFor: coalition1Raw[0][1] as Candidature,
-        points: Number(coalition1Raw[0][2]),
+        points: 0,
       },
       parties: [],
     };
 
     for (const p of parties) {
       for (const k of coalition1Raw[1]) {
         if (k === p.name) {
+          p.points = 0;
           coalition1.parties.push(p);
         }
       }
@@ -120,14 +121,15 @@ export async function main(
       majorCandidate: {
         name: coalition2Raw[0][0],
         candidatesFor: coalition2Raw[0][1] as Candidature,
-        points: Number(coalition2Raw[0][2]),
+        points: 0,
       },
       parties: [],
     };
 
     for (const p of parties) {
       for (const k of coalition2Raw[1]) {
         if (k === p.name) {
+          p.points = 0;
           coalition2.parties.push(p);
         }
       }

election-scripts/types.ts

@@ -33,6 +33,7 @@ export type Candidate = {
 
 export type Party = {
   name: string;
+  points: number;
   councilorCandidates: string[];
 };
 

test/MunicipalityElection.ts

@@ -69,7 +69,6 @@ describe("MunicipalityElection Contract", function () {
 
     expect(coalition[0][0]).to.be.equal(majorCandidate);
     expect(coalition[0][1]).to.be.equal("major");
-    expect(coalition[0][2]).to.be.equal(0);
     expect(coalition[1][0]).to.be.equal(partyName);
     expect(coalition[1][1]).to.be.equal(partyNameB);
   });

zkProtocols/voting/README.md

@@ -0,0 +1,98 @@
+# Municipality Election zk-SNARKS Voting proof 
+
+## About
+
+This program implements a π-vote proof based on a municipality election smart contract deployed using the election-scripts.
+
+The TypeScript script deploy the MunicipalityElection smart contract and registers parties and candidates using mock data.This must be done
+before to generate the proof program.
+
+In a real use case of this program, the circuit for the π-vote proof must be generated after the election 
+registration phase has closed, so that you know the ballot paper used by the Voter to vote.
+
+Following the ballot paper for the municipalityElection generated by the ts script:
+
+```json
+{
+   "contractAddress":"0xa82fF9aFd8f496c3d6ac40E2a0F282E47488CFc9",
+   "coalitions":[
+      {
+         "majorCandidate":{
+            "name":"Pino Pini",
+            "candidatesFor":"major",
+            "points":0
+         },
+         "parties":[
+            {
+               "name":"Partito Democratico",
+               "councilorCandidates":[
+                  "Luigi Rossi",
+                  "Maria Verdi",
+                  "Renato Bianchi",
+                  "Francesco Guidi",
+                  "Paolo Franchi"
+               ],
+               "points":0
+            },
+            {
+               "name":"Forza Italia",
+               "councilorCandidates":[
+                  "Francesca Riti",
+                  "Vanessa Reti",
+                  "Mario Checchi",
+                  "Carlo Proni",
+                  "Pierpaolo Pingitore"
+               ],
+               "points":0
+            }
+         ]
+      },
+      {
+         "majorCandidate":{
+            "name":"Ugo Silenti",
+            "candidatesFor":"major",
+            "points":0
+         },
+         "parties":[
+            {
+               "name":"Cinque Stelle",
+               "councilorCandidates":[
+                  "Giuseppe Toni",
+                  "Nicolò Movizzo",
+                  "Alessandra Tonali",
+                  "Antonella Chierici",
+                  "Antonio Basso"
+               ],
+               "points":0
+            },
+            {
+               "name":"Lega",
+               "councilorCandidates":[
+                  "Patrizio Pini",
+                  "Mariagrazia Crudi",
+                  "Sabrina Giacigli",
+                  "Marco Lioni",
+                  "Pio Pedri"
+               ],
+               "points":0
+            }
+         ]
+      }
+   ]
+}
+```
+
+## Voting mechanism
+
+The election is created assigning 20 voting points (see the `election-scripts/create-election.ts`). 
+
+Therefore, each voter can assign point to the major candidates and/or the parties 
+up to a maximum of 20 points totally.
+
+It is possible to assign points to more that one major candidate at the same time and also to parties in different coalitions.
+
+## What this program proofs
+
+1. The sum of the points assigned to the candidates and the parties does not exceed 20;
+2. Since a voter can assign negative points in that way that the sum is 20, the second proof verifies that the points assigned are positive integers;
+3. The third proof consist to demonstrate that the voter knows for whom he/she is voting;