ECDSA512

Overview

License: MIT

library ECDSA512

Cryptography module

This library provides functionality for ECDSA verification over any 512-bit curve. Currently, this is the most efficient implementation out there, consuming ~13.6 million gas per call.

The approach is Strauss-Shamir double scalar multiplication with 6 bits of precompute + affine coordinates.

Structs info

Parameters

struct Parameters {
    bytes a;
    bytes b;
    bytes gx;
    bytes gy;
    bytes p;
    bytes n;
}

512-bit curve parameters.

_Parameters

struct _Parameters {
    uint512 a;
    uint512 b;
    uint512 gx;
    uint512 gy;
    uint512 p;
    uint512 n;
}

_Inputs

struct _Inputs {
    uint512 r;
    uint512 s;
    uint512 x;
    uint512 y;
}

Functions info

verify

function verify(
    ECDSA512.Parameters memory curveParams_,
    bytes memory hashedMessage_,
    bytes memory signature_,
    bytes memory pubKey_
) internal view returns (bool)

The function to verify the ECDSA signature

Parameters:

Name	Type	Description
curveParams_	struct ECDSA512.Parameters	the 512-bit curve parameters.
hashedMessage_	bytes	the already hashed message to be verified.
signature_	bytes	the ECDSA signature. Equals to bytes(r) + bytes(s).
pubKey_	bytes	the full public key of a signer. Equals to bytes(x) + bytes(y). Note that signatures only from the lower part of the curve are accepted. If your s > n / 2, change it to s = n - s.