╭╯ ECDSA512

Introduction

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 similar to the ECDSA384 library.

Functions

To use the ECDSA512 library, you need to import it.

import "@solarity/solidity-lib/libs/crypto/ECDSA512.sol";

And optionally bind it to the type with the using statement.

using ECDSA512 for *;

verify

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

Description

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

Example

function verifyBrainpoolP512r1(
    bytes calldata message_,
    bytes calldata signature_,
    bytes calldata pubKey_
) external view returns (bool) {
    ECDSA512.Parameters memory curveParams_ =
        ECDSA512.Parameters({
            a: hex"7830a3318b603b89e2327145ac234cc594cbdd8d3df91610a83441caea9863bc2ded5d5aa8253aa10a2ef1c98b9ac8b57f1117a72bf2c7b9e7c1ac4d77fc94ca",
            b: hex"3df91610a83441caea9863bc2ded5d5aa8253aa10a2ef1c98b9ac8b57f1117a72bf2c7b9e7c1ac4d77fc94cadc083e67984050b75ebae5dd2809bd638016f723",
            gx: hex"81aee4bdd82ed9645a21322e9c4c6a9385ed9f70b5d916c1b43b62eef4d0098eff3b1f78e2d0d48d50d1687b93b97d5f7c6d5047406a5e688b352209bcb9f822",
            gy: hex"7dde385d566332ecc0eabfa9cf7822fdf209f70024a57b1aa000c55b881f8111b2dcde494a5f485e5bca4bd88a2763aed1ca2b2fa8f0540678cd1e0f3ad80892",
            p: hex"aadd9db8dbe9c48b3fd4e6ae33c9fc07cb308db3b3c9d20ed6639cca703308717d4d9b009bc66842aecda12ae6a380e62881ff2f2d82c68528aa6056583a48f3",
            n: hex"aadd9db8dbe9c48b3fd4e6ae33c9fc07cb308db3b3c9d20ed6639cca70330870553e5c414ca92619418661197fac10471db1d381085ddaddb58796829ca90069"
        });

    return curveParams_.verify(abi.encodePacked(sha256(message_)), signature_, pubKey_);
}