verify method
verify the sign and the hash of message with the public key
Implementation
bool verify(PublicKey publicKey, String hexHash) {
return base.verify(
base.secp256k1.n,
base.secp256k1.p,
base.secp256k1.a,
base.secp256k1.G,
[publicKey.X, publicKey.Y],
[R, S],
BigInt.parse(hexHash, radix: 16),
);
}