Poseidon in SMT

circuits/smt/smthash_poseidon.circom

@@ -0,0 +1,56 @@
+/*
+    Copyright 2018 0KIMS association.
+
+    This file is part of circom (Zero Knowledge Circuit Compiler).
+
+    circom is a free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    circom is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+    License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with circom. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+include "../poseidon.circom";
+
+
+/*
+    Hash1 = H(1 | key | value)
+ */
+
+template SMTHash1() {
+    signal input key;
+    signal input value;
+    signal output out;
+
+    component h = Poseidon(3, 6, 8, 57);   // Constant
+    h.inputs[0] <== key;
+    h.inputs[1] <== value;
+    h.inputs[2] <== 1;
+
+    out <== h.out;
+}
+
+/*
+    This component is used to create the 2 nodes.
+
+    Hash2 = H(Hl | Hr)
+ */
+
+template SMTHash2() {
+    signal input L;
+    signal input R;
+    signal output out;
+
+    component h = Poseidon(2, 6, 8, 57);   // Constant
+    h.inputs[0] <== L;
+    h.inputs[1] <== R;
+
+    out <== h.out;
+}

circuits/smt/smtprocessor.circom

@@ -135,7 +135,7 @@ include "../switcher.circom";
 include "smtlevins.circom";
 include "smtprocessorlevel.circom";
 include "smtprocessorsm.circom";
-include "smthash.circom";
+include "smthash_poseidon.circom";
 
 template SMTProcessor(nLevels) {
     signal input oldRoot;

circuits/smt/smtverifier.circom

@@ -35,7 +35,7 @@ include "../switcher.circom";
 include "smtlevins.circom";
 include "smtverifierlevel.circom";
 include "smtverifiersm.circom";
-include "smthash.circom";
+include "smthash_poseidon.circom";
 
 template SMTVerifier(nLevels) {
     signal input enabled;

src/smt.js

@@ -1,7 +1,7 @@
 const bigInt = require("snarkjs").bigInt;
 
 const SMTMemDB = require("./smt_memdb");
-const mimc7 = require("./mimc7");
+const {hash0, hash1} = require("./smt_hashes_poseidon");
 
 class SMT {
 
@@ -46,8 +46,8 @@ class SMT {
         const ins = [];
         const dels = [];
 
-        let rtOld = mimc7.multiHash([key, resFind.foundValue], bigInt.one);
+        let rtOld = hash1(key, resFind.foundValue);
-        let rtNew = mimc7.multiHash([key, newValue], bigInt.one);
+        let rtNew = hash1(key, newValue);
         ins.push([rtNew, [1, key, newValue ]]);
         dels.push(rtOld);
 
@@ -62,8 +62,8 @@ class SMT {
                 oldNode = [rtOld, sibling];
                 newNode = [rtNew, sibling];
             }
-            rtOld = mimc7.multiHash(oldNode, bigInt.zero);
+            rtOld = hash0(oldNode[0], oldNode[1]);
-            rtNew = mimc7.multiHash(newNode, bigInt.zero);
+            rtNew = hash0(newNode[0], newNode[1]);
             dels.push(rtOld);
             ins.push([rtNew, newNode]);
         }
@@ -92,7 +92,7 @@ class SMT {
 
         const dels = [];
         const ins = [];
-        let rtOld = mimc7.multiHash([key, resFind.foundValue], bigInt.one);
+        let rtOld = hash1(key, resFind.foundValue);
         let rtNew;
         dels.push(rtOld);
 
@@ -130,9 +130,9 @@ class SMT {
             }
             const oldSibling = resFind.siblings[level];
             if (keyBits[level]) {
-                rtOld = mimc7.multiHash([oldSibling, rtOld], bigInt.zero);
+                rtOld = hash0(oldSibling, rtOld);
             } else {
-                rtOld = mimc7.multiHash([rtOld, oldSibling], bigInt.zero);
+                rtOld = hash0(rtOld, oldSibling);
             }
             dels.push(rtOld);
             if (!newSibling.isZero()) {
@@ -147,7 +147,7 @@ class SMT {
                 } else {
                     newNode = [rtNew, newSibling];
                 }
-                rtNew = mimc7.multiHash(newNode, bigInt.zero);
+                rtNew = hash0(newNode[0], newNode[1]);
                 ins.push([rtNew, newNode]);
             }
         }
@@ -185,7 +185,7 @@ class SMT {
             for (let i= res.siblings.length; oldKeyits[i] == newKeyBits[i]; i++) {
                 res.siblings.push(bigInt.zero);
             }
-            rtOld = mimc7.multiHash([resFind.notFoundKey, resFind.notFoundValue], bigInt.one);
+            rtOld = hash1(resFind.notFoundKey, resFind.notFoundValue);
             res.siblings.push(rtOld);
             addedOne = true;
             mixed = false;
@@ -197,7 +197,7 @@ class SMT {
         const inserts = [];
         const dels = [];
 
-        let rt = mimc7.multiHash([key, value], bigInt.one);
+        let rt = hash1(key, value);
         inserts.push([rt,[1, key, value]] );
 
         for (let i=res.siblings.length-1; i>=0; i--) {
@@ -207,9 +207,9 @@ class SMT {
             if (mixed) {
                 const oldSibling = resFind.siblings[i];
                 if (newKeyBits[i]) {
-                    rtOld = mimc7.multiHash([oldSibling, rtOld], bigInt.zero);
+                    rtOld = hash0(oldSibling, rtOld);
                 } else {
-                    rtOld = mimc7.multiHash([rtOld, oldSibling], bigInt.zero);
+                    rtOld = hash0(rtOld, oldSibling);
                 }
                 dels.push(rtOld);
             }
@@ -217,10 +217,10 @@ class SMT {
 
             let newRt;
             if (newKeyBits[i]) {
-                newRt = mimc7.multiHash([res.siblings[i], rt], bigInt.zero);
+                newRt = hash0(res.siblings[i], rt);
                 inserts.push([newRt,[res.siblings[i], rt]] );
             } else {
-                newRt = mimc7.multiHash([rt, res.siblings[i]],  bigInt.zero);
+                newRt = hash0(rt, res.siblings[i]);
                 inserts.push([newRt,[rt, res.siblings[i]]] );
             }
             rt = newRt;

src/smt_hashes_mimc.js

@@ -0,0 +1,10 @@
+const mimc7 = require("./mimc7");
+const bigInt = require("snarkjs").bigInt;
+
+exports.hash0 = function (left, right) {
+    return mimc7.multiHash(left, right);
+};
+
+exports.hash1 = function(key, value) {
+    return mimc7.multiHash([key, value], bigInt.one);
+};

src/smt_hashes_poseidon.js

@@ -0,0 +1,12 @@
+const Poseidon = require("./poseidon");
+const bigInt = require("snarkjs").bigInt;
+
+const hash = Poseidon.createHash(6, 8, 57);
+
+exports.hash0 = function (left, right) {
+    return hash([left, right]);
+};
+
+exports.hash1 = function(key, value) {
+    return hash([key, value, bigInt.one]);
+};

test/poseidoncontract.js

@@ -46,12 +46,12 @@ describe("Poseidon Smart contract test", () => {
 
         const res = await mimc.methods.poseidon([1,2]).call();
 
-        console.log("Cir: " + bigInt(res.toString(16)).toString(16));
+        // console.log("Cir: " + bigInt(res.toString(16)).toString(16));
 
         const hash = Poseidon.createHash(6, 8, 57);
 
         const res2 = hash([1,2]);
-        console.log("Ref: " + bigInt(res2).toString(16));
+        // console.log("Ref: " + bigInt(res2).toString(16));
 
         assert.equal(res.toString(), res2.toString());
     });

test/smtprocessor.js

@@ -84,7 +84,7 @@ describe("SMT test", function () {
     let circuit;
     let tree;
 
-    this.timeout(100000);
+    this.timeout(10000000);
 
     before( async () => {
         const cirDef = await compiler(path.join(__dirname, "circuits", "smtprocessor10_test.circom"));