ECDSA Signature verification using o1js.

Pure implementaion of ECDSA using only Bigint type.

Library Description.

The file proveableECDSA.ts is the file in which all the logic & modular arithemetic for ECDSA Verification takes place. The function proveableECDSA(...):<Promise:Bool> is the function which recives the data for the verification of a valid Signature.

Tests for modular arithetmics function can be logged by line 225 in proveableECDSA.ts file.

Problem Description.

On running the index.ts file, when the zkProgram has the line assert.assertEquals(checkECDSASignature, "zkAssertion fails?");, the zkProof generation fails with error given below,

workspace_root/src/bindings/ocaml/overrides.js:45
    if (err instanceof Error) throw err;
                              ^
Error: zkAssertion fails?
Bool.assertEquals(): true != false
    at Bool.assertEquals (o1js/src/lib/provable/bool.ts:118:17)
    at method (/Users/soms/zk development/proveableECDSA/src/zkProgram.ts:48:20)
    at Object.constraintSystem (o1js/src/lib/provable/core/provable-context.ts:106:5)
    at analyzeMethods (o1js/src/lib/proof-system/zkprogram.ts:483:45)
    at Object.compile (o1js/src/lib/proof-system/zkprogram.ts:508:23)
    at zkProgramTest (/Users/soms/zk development/proveableECDSA/src/index.ts:22:17)

Node.js v21.7.3

However, keeping everything as-is, and only commenting out the assert.assertEquals(checkECDSASignature, "zkAssertion fails?") in zkProgram. The program gets a valid output displayed on the console.

Inside zkProgram: 71434212616171258881167833273589199798160798266365951356480825534922218147392n
Inside Function : 71434212616171258881167833273589199798160798266365951356480825534922218147392n
Associative property passed.
Commutative property passed.
Identity element passed.
Inverse element passed
Distributivity passed
Scalar multiplication passed
Point doubling passed
Point on curve.
Recovery Point: [
  81447002185398275822095816021075624568224161238760933553486802907392490238292n,
  79251957975174006497705210761697663656081261537861932960031456609646353308556n
]
Siganture recieved: {
  r: 81447002185398275822095816021075624568224161238760933553486802907392490238292n,
  s: 7946449788279160792259694071968415267819694180200632783208719855055985626056n
}
X-affine of RecoveryPoint R == r of signature. Hence valid signature.
Signature is valid.
ECDSA Validation Inside zkProgram true
Is zkProof valid? true

To verify if the test paramters are valid, once can run npx tsx src/proveableECDSA.ts, and it runs a function to test only the ecdsa-verification function. Feel free to modify these accoriding to your own free will.

For the value of e,if message is in plain-text, remember to bytesToHex(sha256(hexToBytes(message))), or use the method verifyECDSA2(...): Promise<boolean>.

How to run?

To run the sample code, which invokes a zkProgram with test-vector values for Signatyre {r,s}, hash(message), & PublicKey{x,y}, you can do npx tsx src/index.ts.

Apache-2.0