What is secp256k1?
The secp256k1 npm package provides an implementation of the elliptic curve secp256k1, which is widely used in cryptographic applications, particularly in blockchain technologies like Bitcoin and Ethereum. This package allows for key generation, signing, and verification of messages using the secp256k1 curve.
What are secp256k1's main functionalities?
Key Generation
This feature allows you to generate a private key and derive the corresponding public key using the secp256k1 curve.
const secp256k1 = require('secp256k1');
const crypto = require('crypto');
// Generate a private key
let privateKey;
do {
privateKey = crypto.randomBytes(32);
} while (!secp256k1.privateKeyVerify(privateKey));
// Generate the public key
const publicKey = secp256k1.publicKeyCreate(privateKey);
console.log('Private Key:', privateKey.toString('hex'));
console.log('Public Key:', publicKey.toString('hex'));
Message Signing
This feature allows you to sign a message hash using a private key, producing a signature and a recovery ID.
const secp256k1 = require('secp256k1');
const crypto = require('crypto');
// Generate a private key
let privateKey;
do {
privateKey = crypto.randomBytes(32);
} while (!secp256k1.privateKeyVerify(privateKey));
// Create a message hash
const message = 'Hello, world!';
const msgHash = crypto.createHash('sha256').update(message).digest();
// Sign the message hash
const sigObj = secp256k1.ecdsaSign(msgHash, privateKey);
console.log('Signature:', sigObj.signature.toString('hex'));
console.log('Recovery ID:', sigObj.recid);
Signature Verification
This feature allows you to verify a signature against a message hash and a public key, ensuring the authenticity of the message.
const secp256k1 = require('secp256k1');
const crypto = require('crypto');
// Generate a private key
let privateKey;
do {
privateKey = crypto.randomBytes(32);
} while (!secp256k1.privateKeyVerify(privateKey));
// Generate the public key
const publicKey = secp256k1.publicKeyCreate(privateKey);
// Create a message hash
const message = 'Hello, world!';
const msgHash = crypto.createHash('sha256').update(message).digest();
// Sign the message hash
const sigObj = secp256k1.ecdsaSign(msgHash, privateKey);
// Verify the signature
const isValid = secp256k1.ecdsaVerify(sigObj.signature, msgHash, publicKey);
console.log('Signature is valid:', isValid);
Other packages similar to secp256k1
elliptic
The elliptic package is a general-purpose elliptic curve library that supports multiple curves, including secp256k1. It provides similar functionalities for key generation, signing, and verification but also supports other curves like ed25519 and p256. It is more versatile but may be more complex to use for secp256k1-specific applications.
bitcoinjs-lib
The bitcoinjs-lib package is a comprehensive library for Bitcoin-related operations, including key generation, signing, and verification using secp256k1. While it offers similar functionalities, it is more specialized for Bitcoin and includes additional features like transaction creation and parsing.
noble-secp256k1
The noble-secp256k1 package is a modern, fast, and secure implementation of the secp256k1 elliptic curve. It focuses on performance and security, providing similar functionalities for key generation, signing, and verification. It is a good alternative if performance and security are critical.
SYNOPSIS
This module provides native bindings to ecdsa secp256k1 functions.
This library is experimental, so use at your own risk.
INSTALL
If you have gmp installed secp256k1 will use it. Otherwise it should fallback to openssl.
- arch
pacman -S gmp
- ubuntu
sudo apt-get install libgmp-dev
from npm
npm install secp256k1
from git
git clone git@github.com:wanderer/secp256k1-node.git
cd secp256k1-node
git submodule init
git submodule update
npm install
USAGE
var ecdsa = require('secp256k1')
var crypto = require('crypto')
var privateKey = crypto.randomBytes(32)
var msg = crypto.randomBytes(32)
var pubKey = ecdsa.createPublicKey(privateKey, true)
var sig = ecdsa.sign(msg, privateKey)
if(ecdsa.verify(msg, sig, pubKey)){
console.log("valid signature")
}
TEST
run npm test
API
Signature
All functions that take signatures can take two formats
- DER - which should be a repersented as an
Buffer
- Compact - which should be an
Object
with the following
signature
- a Buffer
recovery
- an Integer
for the recovery id
secp256k1.verifySecretKey(secretKey)
Verify an ECDSA secret key.
Parameters
- secretKey -
Buffer
, the secret Key to verify
Returns: Boolean
, true
if secret key is valid, false
secret key is invalid
secp256k1.verifyPublicKey(publicKey)
Verify an ECDSA public key.
Parameters
- publicKey -
Buffer
, the public Key to verify
Returns: Boolean
, true
if public key is valid, false
secret key is invalid
secp256k1.sign(msg, secretkey, [DER], [cb])
Create an ECDSA signature.
Parameters
- msg -
Buffer
, a 32-byte message hash being signed - secretkey -
Buffer
, a 32-byte secret key (assumed to be valid) - DER -
Boolean
, Optional if true
the signature produced will be in DER format. Defaults to false
- cb -
function
, Optional the callback. The callback is given the signature. If no callback is given the function will run sync.
Returns:
- if
DER
a Buffer
, if no callback is given a 72-byte signature is returned - else an compact siganture
Object
secp256k1.verify(mgs, sig, pubKey, [cb])
Verify an ECDSA signature. Runs asynchronously if given a callback
Parameters
- mgs -
Buffer
, the 32-byte message hash being verified - sig -
Buffer
, the signature being verified - pubKey -
Buffer
, the public key - cb - a callback if you want to run async
Returns: Integer,
- true correct signature
- false incorrect signature
secp256k1.recover(msg, sig, compressed, [cb])
Recover an ECDSA public key from a compact signature in the process also verifing it. Runs asynchronously if given a callback
Parameters
- msg -
Buffer
, the message assumed to be signed - sig -
Buffer
, the signature - compressed -
Boolean
, whether to recover a compressed or uncompressed pubkey. Defaults to true
- cb -
function
, Recover an ECDSA public key from a compact signature. In the process also verifing it.
Returns: Buffer, the pubkey, a 33 or 65 byte buffer
secp256k1.createPublicKey(secKey, compressed)
Compute the public key for a secret key.
Parameters
- secKey -
Buffer
, a 32-byte private key. - compressed -
Boolean
, whether the computed public key should be compressed
Returns: Buffer, a 33-byte (if compressed) or 65-byte (if uncompressed).
secp256k1.exportPrivateKey(secretKey, compressed)
Parameters
- secretKey -
Buffer
- compressed -
Boolean
** Returns**: Buffer, privateKey
secp256k1.importPrivateKey(privateKey)
Parameters
Returns: Buffer
, secretKey
secp256k1.decompressPublickey(secretKey)
Parameters
Returns: Buffer
, This module provides native bindings to ecdsa secp256k1 functions
secp256k1.privKeyTweakAdd(secretKey)
Parameters
- privateKey -
Buffer
- tweak -
Buffer
Returns: Buffer
secp256k1.privKeyTweakMul(privateKey, tweak)
Parameters
- privateKey -
Buffer
- tweak -
Buffer
Returns: Buffer
LICENSE
MIT