Poseidon for t=3

src/poseidon.js

@@ -36,6 +36,8 @@ exports.getMatrix = (t, seed, nRounds) => {
     if (typeof seed === "undefined") seed = SEED;
     if (typeof nRounds === "undefined") nRounds = NROUNDSF + NROUNDSP;
     if (typeof t === "undefined") t = T;
+    assert(t<=6);  // Force the same matrix for all.
+    t=6;
     let nonce = "0000";
     let cmatrix = getPseudoRandom(seed+"_matrix_"+nonce, t*2);
     while (!allDifferent(cmatrix)) {

src/poseidon_gencontract.js

@@ -121,7 +121,7 @@ function createCode(t, nRoundsF, nRoundsP, seed) {
     // We ignore the pointer and the length and just load 6 values to the state
     // (Stack positions 0-5) If the array is shorter, we just set zeros.
     for (let i=0; i<t; i++) {
-        C.push(0x44+(0x20*(5-i)));
+        C.push(0x44+(0x20*(t-1-i)));
         C.calldataload();
     }
 

test/circuits/poseidon3_test.circom

@@ -0,0 +1,3 @@
+include "../../circuits/poseidon.circom"
+
+component main = Poseidon(2, 3, 8, 57);

test/poseidoncircuit.js

@@ -18,43 +18,74 @@ describe("Blake2b version test", function() {
 });
 
 describe("Poseidon Circuit test", function () {
-    let circuit;
+    let circuit6;
+    let circuit3;
 
     this.timeout(100000);
 
     before( async () => {
-        const cirDef = await compiler(path.join(__dirname, "circuits", "poseidon_test.circom"));
-
-        circuit = new snarkjs.Circuit(cirDef);
-
-        console.log("Poseidon constraints: " + circuit.nConstraints);
+        const cirDef6 = await compiler(path.join(__dirname, "circuits", "poseidon6_test.circom"));
+        circuit6 = new snarkjs.Circuit(cirDef6);
+        console.log("Poseidon6 constraints: " + circuit6.nConstraints);
+        const cirDef3 = await compiler(path.join(__dirname, "circuits", "poseidon3_test.circom"));
+        circuit3 = new snarkjs.Circuit(cirDef3);
+        console.log("Poseidon3 constraints: " + circuit3.nConstraints);
     });
 
-    it("Should check constrain of hash([1, 2])", async () => {
-        const w = circuit.calculateWitness({inputs: [1, 2]});
+    it("Should check constrain of hash([1, 2]) t=6", async () => {
+        const w = circuit6.calculateWitness({inputs: [1, 2]});
 
-        const res = w[circuit.getSignalIdx("main.out")];
+        const res = w[circuit6.getSignalIdx("main.out")];
 
         const hash = poseidon.createHash(6, 8, 57);
 
         const res2 = hash([1,2]);
-        assert.equal('12242166908188651009877250812424843524687801523336557272219921456462821518061', res2.toString());
+        assert.equal("12242166908188651009877250812424843524687801523336557272219921456462821518061", res2.toString());
         assert.equal(res.toString(), res2.toString());
-        assert(circuit.checkWitness(w));
+        assert(circuit6.checkWitness(w));
     });
 
-    it("Should check constrain of hash([3, 4])", async () => {
-        const w = circuit.calculateWitness({inputs: [3, 4]});
+    it("Should check constrain of hash([3, 4]) t=6", async () => {
+        const w = circuit6.calculateWitness({inputs: [3, 4]});
 
-        const res = w[circuit.getSignalIdx("main.out")];
+        const res = w[circuit6.getSignalIdx("main.out")];
 
         const hash = poseidon.createHash(6, 8, 57);
 
         const res2 = hash([3, 4]);
-        assert.equal('17185195740979599334254027721507328033796809509313949281114643312710535000993', res2.toString());
+        assert.equal("17185195740979599334254027721507328033796809509313949281114643312710535000993", res2.toString());
 
         assert.equal(res.toString(), res2.toString());
 
-        assert(circuit.checkWitness(w));
+        assert(circuit6.checkWitness(w));
+    });
+
+
+    it("Should check constrain of hash([1, 2]) t=3", async () => {
+        const w = circuit3.calculateWitness({inputs: [1, 2]});
+
+        const res = w[circuit3.getSignalIdx("main.out")];
+
+        const hash = poseidon.createHash(3, 8, 57);
+
+        const res2 = hash([1,2]);
+        assert.equal("2104035019328376391822106787753454168168617545136592089411833517434990977743", res2.toString());
+        assert.equal(res.toString(), res2.toString());
+        assert(circuit3.checkWitness(w));
+    });
+
+    it("Should check constrain of hash([3, 4]) t=3", async () => {
+        const w = circuit3.calculateWitness({inputs: [3, 4]});
+
+        const res = w[circuit3.getSignalIdx("main.out")];
+
+        const hash = poseidon.createHash(3, 8, 57);
+
+        const res2 = hash([3, 4]);
+        assert.equal("12456141564250880945411182508630957604732712316993112736876413121277158512223", res2.toString());
+
+        assert.equal(res.toString(), res2.toString());
+
+        assert(circuit3.checkWitness(w));
     });
 });

test/poseidoncontract.js

@@ -8,13 +8,13 @@ const bigInt = require("snarkjs").bigInt;
 const assert = chai.assert;
 const log = (msg) => { if (process.env.MOCHA_VERBOSE) console.log(msg); };
 
-const SEED = "mimc";
-
-describe("Poseidon Smart contract test", () => {
+describe("Poseidon Smart contract test", function () {
     let testrpc;
     let web3;
-    let mimc;
+    let poseidon6;
+    let poseidon3;
     let accounts;
+    this.timeout(100000);
 
     before(async () => {
         web3 = new Web3(ganache.provider(), null, { transactionConfirmationBlocks: 1 });
@@ -24,17 +24,23 @@ describe("Poseidon Smart contract test", () => {
     it("Should deploy the contract", async () => {
         const C = new web3.eth.Contract(poseidonGenContract.abi);
 
-        mimc = await C.deploy({
-            data: poseidonGenContract.createCode()
+        poseidon6 = await C.deploy({
+            data: poseidonGenContract.createCode(6)
+        }).send({
+            gas: 2500000,
+            from: accounts[0]
+        });
+        poseidon3 = await C.deploy({
+            data: poseidonGenContract.createCode(3)
         }).send({
             gas: 2500000,
             from: accounts[0]
         });
     });
 
-    it("Shold calculate the mimic correctly", async () => {
+    it("Shold calculate the poseidon correctly t=6", async () => {
 
-        const res = await mimc.methods.poseidon([1,2]).call();
+        const res = await poseidon6.methods.poseidon([1,2]).call();
 
         // console.log("Cir: " + bigInt(res.toString(16)).toString(16));
 
@@ -45,5 +51,19 @@ describe("Poseidon Smart contract test", () => {
 
         assert.equal(res.toString(), res2.toString());
     });
+    it("Shold calculate the poseidon correctly t=3", async () => {
+
+        const res = await poseidon3.methods.poseidon([1,2]).call();
+
+        // console.log("Cir: " + bigInt(res.toString(16)).toString(16));
+
+        const hash = Poseidon.createHash(3, 8, 57);
+
+        const res2 = hash([1,2]);
+        // console.log("Ref: " + bigInt(res2).toString(16));
+
+        assert.equal(res.toString(), res2.toString());
+    });
+
 });