🔍 Key HumanID with its least significant 16 bits in Merkle Tree. (fixes #15)

Author: KimlikDAO-bot

mina/examples/Airdrop.ts

@@ -5,7 +5,7 @@ import {
   method,
   state
 } from "o1js";
-import { EmptyRoot, HumanIDWitness, Signatures, authenticate, requireUnique } from "../humanIDv1";
+import { EmptyRoot, HumanIDWitness, Signatures, acceptHumanIDv1 } from "../humanIDv1";
 
 /**
  * Example airdrop zkApp, which gives 10 MINA rewards to the first 1000
@@ -24,8 +24,7 @@ class Airdrop extends SmartContract {
     sigs: Signatures,
     witness: HumanIDWitness,
   ) {
-    authenticate(humanIDv1, sigs, witness.calculateIndex());
-    requireUnique(this.treeRoot, witness);
+    acceptHumanIDv1(humanIDv1, sigs, this.treeRoot, witness);
   }
 }
 

mina/humanIDv1.ts

@@ -8,7 +8,7 @@ class Signatures extends Struct({
 
 class HumanIDWitness extends MerkleWitness(16) { }
 
-const requireUnique = (treeRoot: State<Field>, witness: HumanIDWitness) => {
+const addToMerkleTree = (treeRoot: State<Field>, witness: HumanIDWitness) => {
   const currentTreeRoot = treeRoot.getAndRequireEquals();
   currentTreeRoot.assertEquals(
     witness.calculateRoot(Field(0)),
@@ -17,11 +17,35 @@ const requireUnique = (treeRoot: State<Field>, witness: HumanIDWitness) => {
   treeRoot.set(witness.calculateRoot(Field(1)));
 }
 
-const authenticate = (humanIDv1: Field, sigs: Signatures, truncatedHumanID: Field) => {
+const authenticate = (humanIDv1: Field, sigs: Signatures) => {
   // TODO(KimlikDAO-bot)
   return true;
 }
 
 const EmptyRoot = Field(0xccdd9994da4ffb1d39fcdf50d2c2c6240c423d6ec332865eea991c7bf1e5a9cn);
 
-export { EmptyRoot, HumanIDWitness, Signatures, authenticate, requireUnique };
+const requireConsistent = (humanIDv1: Field, truncatedHumanIDv1: Field) => {
+  humanIDv1.sub(truncatedHumanIDv1).div(65536)
+    .assertLessThan((1n << 238n) + 0x224698fc094cf91b992d30ed0000n);
+}
+
+const acceptHumanIDv1 = (
+  humanIDv1: Field,
+  sigs: Signatures,
+  treeRoot: State<Field>,
+  witness: HumanIDWitness
+) => {
+  authenticate(humanIDv1, sigs);
+  requireConsistent(humanIDv1, witness.calculateIndex());
+  addToMerkleTree(treeRoot, witness);
+}
+
+export {
+  EmptyRoot,
+  HumanIDWitness,
+  Signatures,
+  acceptHumanIDv1,
+  addToMerkleTree,
+  authenticate,
+  requireConsistent
+};