noble-secp256k1
Fastest JS implementation of secp256k1, an elliptic curve that could be used for asymmetric encryption, ECDH key agreement protocol and signature schemes. Supports deterministic ECDSA from RFC6979 and Schnorr signatures from BIP0340.
Audited with crowdfunding by an independent security firm. Tested against thousands of test vectors from a different library. Check out the online demo and blog post: Learning fast elliptic-curve cryptography in JS
This library belongs to noble crypto
noble-crypto â high-security, easily auditable set of contained cryptographic libraries and tools.
- No dependencies, one small file
- Easily auditable TypeScript/JS code
- Supported in all major browsers and stable node.js versions
- All releases are signed with PGP keys
- Check out homepage & all libraries: secp256k1, ed25519, bls12-381, hashes
Usage
Use NPM in node.js / browser, or include single file from GitHubâs releases page:
npm install @noble/secp256k1
// Common.js and ECMAScript Modules (ESM)
import * as secp from "@noble/secp256k1";
// If you're using single file, use global variable instead:
// nobleSecp256k1
(async () => {
// You pass a hex string, or Uint8Array
const privateKey = "6b911fd37cdf5c81d4c0adb1ab7fa822ed253ab0ad9aa18d77257c88b29b718e";
const message = "hello world";
const messageHash = await secp.utils.sha256(message);
const publicKey = secp.getPublicKey(privateKey);
const signature = await secp.sign(messageHash, privateKey);
const isSigned = secp.verify(signature, messageHash, publicKey);
// Sigs with improved security (see README)
const signatureE = await secp.sign(messageHash, privateKey, { extraEntropy: true });
// Malleable signatures, compatible with openssl
const signatureM = await secp.sign(messageHash, privateKey, { canonical: false });
// Supports Schnorr signatures
const rpub = secp.schnorr.getPublicKey(privateKey);
const rsignature = await secp.schnorr.sign(message, privateKey);
const risSigned = await secp.schnorr.verify(rsignature, message, rpub);
})();
To use the module with Deno, you will need import map:
deno run --import-map=imports.json app.ts
app.ts
import * as secp from "https://deno.land/x/secp256k1/mod.ts"; const publicKey = secp.getPublicKey(secp.utils.randomPrivateKey()); console.log(publicKey);
imports.json
{ "imports": { "crypto": "https://deno.land/std@0.119.0/node/crypto.ts" } }
API
getPublicKey(privateKey)
getSharedSecret(privateKeyA, publicKeyB)
sign(msgHash, privateKey)
verify(signature, msgHash, publicKey)
recoverPublicKey(hash, signature, recovery)
schnorr.getPublicKey(privateKey)
schnorr.sign(hash, privateKey)
schnorr.verify(signature, hash, publicKey)
- Helpers
getPublicKey(privateKey)
function getPublicKey(privateKey: Uint8Array | string | bigint, isCompressed = false): Uint8Array;
privateKey
will be used to generate public key.
Public key is generated by doing scalar multiplication of a base Point(x, y) by a fixed
integer. The result is another Point(x, y)
which we will by default encode to hex Uint8Array.
isCompressed
(default is false
) determines whether the output should contain y
coordinate of the point.
To get Point instance, use Point.fromPrivateKey(privateKey)
.
getSharedSecret(privateKeyA, publicKeyB)
function getSharedSecret(privateKeyA: Uint8Array | string | bigint, publicKeyB: Uint8Array | string | Point): Uint8Array;
Computes ECDH (Elliptic Curve Diffie-Hellman) shared secret between a private key and a different public key.
To get Point instance, use Point.fromHex(publicKeyB).multiply(privateKeyA)
.
To speed-up the function massively by precomputing EC multiplications,
use getSharedSecret(privateKeyA, secp.utils.precompute(8, publicKeyB))
sign(msgHash, privateKey)
function sign(msgHash: Uint8Array | string, privateKey: Uint8Array | string, opts?: Options): Promise<Uint8Array>;
function sign(msgHash: Uint8Array | string, privateKey: Uint8Array | string, opts?: Options): Promise<[Uint8Array, number]>;
Generates low-s deterministic ECDSA signature as per RFC6979.
Itâs strongly recommended to pass {extraEntropy: true}
to improve security of signatures:
- In case the entropy generator is broken, signatures would be just like they are without the option
- It would help a lot in case there is an error somewhere in
k
generation. Exposingk
could leak private keys - Schnorr signatures are adding extra entropy every time
- The only disadvantage to this is the fact signatures wonât be exactly equal to fully-deterministic sigs; think backwards-compatibility with test vectors. They would still be valid, though
sign
arguments:
msgHash: Uint8Array | string
- message hash which would be signedprivateKey: Uint8Array | string | bigint
- private key which will sign the hashoptions?: Options
- optional object related to signature value and formatoptions?.recovered: boolean = false
- whether the recovered bit should be included in the result. In this case, the result would be an array of two items.options?.canonical: boolean = true
- whether a signatures
should be no more than 1/2 prime order.true
makes signatures compatible with libsecp256k1,false
makes signatures compatible with openssloptions?.extraEntropy: Uint8Array | string | true
- additional entropyk'
for deterministic signature, follows section 3.6 of RFC6979. Whentrue
, it would automatically be filled with 32 bytes of cryptographically secure entropyoptions?.der: boolean = true
- whether the returned signature should be in DER format. Iffalse
, it would be in Compact format (32-byte r + 32-byte s)
The function is asynchronous because weâre utilizing built-in HMAC API to not rely on dependencies.
signSync
counterpart could also be used, you need to set utils.hmacSha256Sync
to a function with signature key: Uint8Array, ...messages: Uint8Array[]) => Uint8Array
. Example with noble-hashes
package:
const { hmac } = require('@noble/hashes/hmac');
const { sha256 } = require('@noble/hashes/sha256');
secp256k1.utils.hmacSha256Sync = (key: Uint8Array, ...msgs: Uint8Array[]) => {
const h = hmac.create(sha256, key);
msgs.forEach(msg => h.update(msg));
return h.digest();
};
// Can be used now
secp256k1.signSync(msgHash, privateKey)
verify(signature, msgHash, publicKey)
function verify(signature: Uint8Array | string, msgHash: Uint8Array | string, publicKey: Uint8Array | string): boolean
function verify(signature: Signature, msgHash: Uint8Array | string, publicKey: Point): boolean
signature: Uint8Array | string | { r: bigint, s: bigint }
- object returned by thesign
functionmsgHash: Uint8Array | string
- message hash that needs to be verifiedpublicKey: Uint8Array | string | Point
- e.g. that was generated fromprivateKey
bygetPublicKey
options?: Options
- optional object related to signature value and formatoptions?.strict: boolean = true
- whether a signatures
should be no more than 1/2 prime order.true
makes signatures compatible with libsecp256k1,false
makes signatures compatible with openssl- Returns
boolean
:true
ifsignature == hash
; otherwisefalse
recoverPublicKey(hash, signature, recovery)
function recoverPublicKey(msgHash: Uint8Array | string, signature: Uint8Array | string, recovery: number): Uint8Array | undefined;
msgHash: Uint8Array | string
- message hash which would be signedsignature: Uint8Array | string | { r: bigint, s: bigint }
- object returned by thesign
functionrecovery: number
- recovery bit returned bysign
withrecovered
option Public key is generated by doing scalar multiplication of a base Point(x, y) by a fixed integer. The result is anotherPoint(x, y)
which we will by default encode to hex Uint8Array. If signature is invalid - function will returnundefined
as result.
To get Point instance, use Point.fromSignature(hash, signature, recovery)
.
schnorr.getPublicKey(privateKey)
function schnorrGetPublicKey(privateKey: Uint8Array | string): Uint8Array;
Returns 32-byte public key. Warning: it is incompatible with non-schnorr pubkey.
Specifically, its y coordinate may be flipped. See BIP340 for clarification.
schnorr.sign(hash, privateKey)
function schnorrSign(msgHash: Uint8Array | string, privateKey: Uint8Array | string, auxilaryRandom?: Uint8Array): Promise<Uint8Array>;
Generates Schnorr signature as per BIP0340. Asynchronous, so use await
.
msgHash: Uint8Array | string
- message hash which would be signedprivateKey: Uint8Array | string | bigint
- private key which will sign the hashauxilaryRandom?: Uint8Array
â optional 32 random bytes. By default, the method gathers cryptogarphically secure entropy- Returns Schnorr signature in Hex format.
schnorr.verify(signature, hash, publicKey)
function schnorrVerify(signature: Uint8Array | string, msgHash: Uint8Array | string, publicKey: Uint8Array | string): boolean
signature: Uint8Array | string | { r: bigint, s: bigint }
- object returned by thesign
functionmsgHash: Uint8Array | string
- message hash that needs to be verifiedpublicKey: Uint8Array | string | Point
- e.g. that was generated fromprivateKey
bygetPublicKey
- Returns
boolean
:true
ifsignature == hash
; otherwisefalse
Point methods
Helpers
utils.randomBytes(): Uint8Array
Returns Uint8Array
of 32 cryptographically secure random bytes.
Uses crypto.web.getRandomValues
in browser, require('crypto').randomBytes
in node.js.
utils.randomPrivateKey(): Uint8Array
Returns Uint8Array
of 32 cryptographically secure random bytes that can be used as private key. The signature is:
(key: Uint8Array, ...msgs: Uint8Array[]): Uint8Array;
utils.bytesToHex(bytes: Uint8Array): string
Converts a byte array to hex string.
utils.sha256
and utils.hmacSha256
Asynchronous methods that calculate SHA256
and HMAC-SHA256
. Use browser built-ins by default.
utils.sha256Sync
and utils.hmacSha256Sync
The functions are not defined by default, but could be used to implement signSync
method (see above).
utils.precompute(W = 8, point = BASE_POINT): Point
Returns cached point which you can use to pass to getSharedSecret
or to #multiply
by it.
This is done by default, no need to run it unless you want to disable precomputation or change window size.
Weâre doing scalar multiplication (used in getPublicKey etc) with precomputed BASE_POINT values.
This slows down first getPublicKey() by milliseconds (see Speed section), but allows to speed-up subsequent getPublicKey() calls up to 20x.
You may want to precompute values for your own point.
secp256k1.CURVE.P // Field, 2 ** 256 - 2 ** 32 - 977
secp256k1.CURVE.n // Order, 2 ** 256 - 432420386565659656852420866394968145599
secp256k1.Point.BASE // new secp256k1.Point(Gx, Gy) where
// Gx = 55066263022277343669578718895168534326250603453777594175500187360389116729240n
// Gy = 32670510020758816978083085130507043184471273380659243275938904335757337482424n;
// Elliptic curve point in Affine (x, y) coordinates.
secp256k1.Point {
constructor(x: bigint, y: bigint);
// Supports compressed and non-compressed hex
static fromHex(hex: Uint8Array | string);
static fromPrivateKey(privateKey: Uint8Array | string | number | bigint);
static fromSignature(
msgHash: Hex,
signature: Signature,
recovery: number | bigint
): Point | undefined {
toRawBytes(isCompressed = false): Uint8Array;
toHex(isCompressed = false): string;
equals(other: Point): boolean;
negate(): Point;
add(other: Point): Point;
subtract(other: Point): Point;
// Constant-time scalar multiplication.
multiply(scalar: bigint | Uint8Array): Point;
}
secp256k1.Signature {
constructor(r: bigint, s: bigint);
// DER encoded ECDSA signature
static fromDER(hex: Uint8Array | string);
// R, S 32-byte each
static fromCompact(hex: Uint8Array | string);
assertValidity(): void;
hasHighS(): boolean; // high-S sigs cannot be produced using { canonical: true }
toDERRawBytes(): Uint8Array;
toDERHex(): string;
toCompactRawBytes(): Uint8Array;
toCompactHex(): string;
}
Security
Noble is production-ready.
- The library has been audited by an independent security firm cure53: PDF. The audit has been crowdfunded by community with help of Umbra.cash.
- The library has also been fuzzed by Guido Vrankenâs cryptofuzz. You can run the fuzzer by yourself to check it.
Weâre using built-in JS BigInt
, which is âunsuitable for use in cryptographyâ as per official spec. This means that the lib is potentially vulnerable to timing attacks. But, JIT-compiler and Garbage Collector make âconstant timeâ extremely hard to achieve in a scripting language. Which means any other JS library doesnât use constant-time bigints. Including bn.js or anything else. Even statically typed Rust, a language without GC, makes it harder to achieve constant-time for some cases. If your goal is absolute security, donât use any JS lib â including bindings to native ones. Use low-level libraries & languages. Nonetheless weâve hardened implementation of koblitz curve multiplication to be algorithmically constant time.
We however consider infrastructure attacks like rogue NPM modules very important; thatâs why itâs crucial to minimize the amount of 3rd-party dependencies & native bindings. If your app uses 500 dependencies, any dep could get hacked and youâll be downloading malware with every npm install
. Our goal is to minimize this attack vector.
Speed
Benchmarks measured with Apple M1 on MacOS 12.
getPublicKey(utils.randomPrivateKey()) x 6,216 ops/sec @ 160Îźs/op
sign x 4,789 ops/sec @ 208Îźs/op
verify x 923 ops/sec @ 1ms/op
recoverPublicKey x 491 ops/sec @ 2ms/op
getSharedSecret aka ecdh x 558 ops/sec @ 1790Îźs/op
getSharedSecret (precomputed) x 7,105 ops/sec @ 140Îźs/op
Point.fromHex (decompression) x 12,171 ops/sec @ 82Îźs/op
schnorr.sign x 409 ops/sec @ 2ms/op
schnorr.verify x 504 ops/sec @ 1ms/op
Compare to other libraries (openssl
uses native bindings, not JS):
elliptic#getPublicKey x 1,940 ops/sec
sjcl#getPublicKey x 211 ops/sec
elliptic#sign x 1,808 ops/sec
sjcl#sign x 199 ops/sec
openssl#sign x 4,243 ops/sec
ecdsa#sign x 116 ops/sec
bip-schnorr#sign x 60 ops/sec
elliptic#verify x 812 ops/sec
sjcl#verify x 166 ops/sec
openssl#verify x 4,452 ops/sec
ecdsa#verify x 80 ops/sec
bip-schnorr#verify x 56 ops/sec
elliptic#ecdh x 971 ops/sec
Contributing
Check out a blog post about this library: Learning fast elliptic-curve cryptography in JS.
- Clone the repository.
npm install
to install build dependencies like TypeScriptnpm run compile
to compile TypeScript codenpm run test
to run jest ontest/index.ts
Special thanks to Roman Koblov, who have helped to improve scalar multiplication speed.
License
MIT (c) Paul Miller (https://paulmillr.com), see LICENSE file.