ECDSA sign/verify code: update

[nakov]

Regarding ECDSA, I found this to work for the latest release of pycoin:

https://cryptobook.nakov.com/digital-signatures/ecdsa-sign-verify-examples#ecdsa-sign-verify-using-the-secp-256-k1-curve-and-sha-3-256

from pycoin.ecdsa.secp256k1 import secp256k1_generator import hashlib, secrets

def sha3_256Hash(msg): hashBytes = hashlib.sha3_256(msg.encode("utf8")).digest() print(f'msgHash={hashBytes.hex()}') return int.from_bytes(hashBytes, byteorder="big")

def signECDSAsecp256k1(msg, privKey): msgHash = sha3_256Hash(msg) signature = secp256k1_generator.sign(privKey, msgHash) return signature

def verifyECDSAsecp256k1(msg, signature, pubKey): msgHash = sha3_256Hash(msg) valid = secp256k1_generator.verify(pubKey, msgHash, signature) return valid

ECDSA sign message (using the curve secp256k1 + SHA3-256)

msg = "Message for ECDSA signing" privKey = secrets.randbelow(secp256k1_generator.order()) signature = signECDSAsecp256k1(msg, privKey) print("Message:", msg) print("Private key:", hex(privKey)) print("Signature: r=" + hex(signature[0]) + ", s=" + hex(signature[1]))

ECDSA verify signature (using the curve secp256k1 + SHA3-256)

pubKey = secp256k1_generator * privKey valid = verifyECDSAsecp256k1(msg, signature, pubKey) print("\nMessage:", msg) print("Public key: (" + hex(pubKey[0]) + ", " + hex(pubKey[1]) + ")") print("Signature valid?", valid)

ECDSA verify tampered signature (using the curve secp256k1 + SHA3-256)

msg = "Tampered message" valid = verifyECDSAsecp256k1(msg, signature, pubKey) print("\nMessage:", msg) print("Signature (tampered msg) valid?", valid)

Cheers!

Mark von der Lieth