🙃 Replace Field.div() with Field.mul() (faster)

Author: KimlikDAO-bot

mina/examples/Airdrop.test.ts

@@ -70,7 +70,7 @@ describe('Example Airdrop zkApp', () => {
     await fundZkApp();
 
     const id1 = 123123123123123123123123123123n;
-    const truncatedId1 = id1 % (1n << 32n);
+    const truncatedId1 = id1 & 0xFFFFFFFFn;
     await Mina.transaction(
       sender,
       () => app.claimReward(Field(id1), sigs, new HumanIDWitness(tree.getWitness(truncatedId1)))
@@ -81,7 +81,7 @@ describe('Example Airdrop zkApp', () => {
     tree.setLeaf(truncatedId1, Field(1));
 
     const id2 = 123123123123123123123123123124n;
-    const truncatedId2 = id2 % (1n << 32n);
+    const truncatedId2 = id2 & 0xFFFFFFFFn;
     await Mina.transaction(
       sender,
       () => app.claimReward(Field(id2), sigs, new HumanIDWitness(tree.getWitness(truncatedId2)))

mina/humanIDv1.ts

@@ -24,8 +24,10 @@ const authenticate = (humanIDv1: Field, sigs: Signatures) => {
 
 const EmptyRoot = Field(0x21afce36daa1a2d67391072035f4555a85aea7197e5830b128f121aa382770cdn);
 
+const Inverse2Exp32 = Field(0x3fffffffc00000000000000000000000224698fbe706601f8fe037d166d2cf14n);
+
 const requireConsistent = (humanIDv1: Field, truncatedHumanIDv1: Field) => {
-  humanIDv1.sub(truncatedHumanIDv1).div(1n << 32n).assertLessThan(
+  humanIDv1.sub(truncatedHumanIDv1).mul(Inverse2Exp32).assertLessThan(
     (1n << 222n) + 0x224698fc094cf91b992d30edn,
     "HumanID does not match the witness"
   );