@noble/curves
Advanced tools
The @noble/curves npm package is a library that provides a collection of elliptic curves, allowing for the implementation of cryptographic operations such as digital signatures and key agreement protocols. It is part of the noble family of cryptographic libraries, which are known for their focus on security, simplicity, and small bundle size.
Elliptic Curve Cryptography (ECC) Operations
This code demonstrates how to generate a private key, derive its corresponding public key, sign a message, and verify the signature using the P-256 elliptic curve. It showcases the basic cryptographic operations that can be performed with the @noble/curves package.
"use strict";
const curves = require('@noble/curves');
const { p256 } = curves;
async function main() {
const privateKey = p256.utils.randomPrivateKey();
const publicKey = p256.getPublicKey(privateKey);
const message = new TextEncoder().encode('Hello, world!');
const signature = await p256.sign(message, privateKey);
const isValid = await p256.verify(signature, message, publicKey);
console.log('Signature valid:', isValid);
}
main();Elliptic is a popular npm package that provides implementations of various elliptic curve cryptography algorithms. It supports a wide range of curves and cryptographic operations, making it a versatile choice for many applications. Compared to @noble/curves, Elliptic may offer a broader selection of curves but might not have the same focus on minimalism and security.
Bcrypto is a node.js and web cryptography library that supports a variety of cryptographic primitives, including elliptic curve cryptography. It is designed for high performance and security, offering a comprehensive suite of cryptographic functions. Bcrypto and @noble/curves share a focus on security, but bcrypto provides a wider range of cryptographic functionalities beyond just elliptic curves.
Audited & minimal JS implementation of elliptic curve cryptography.
Check out Upgrading if you've previously used single-feature noble packages. See Resources for articles and real-world software that uses curves.
noble-crypto — high-security, easily auditable set of contained cryptographic libraries and tools.
Browser, deno and node.js are supported:
npm install @noble/curves
For Deno, use it with npm specifier. In browser, you could also include the single file from GitHub's releases page.
The library is tree-shaking-friendly and does NOT expose root entry point as
import c from '@noble/curves'. Instead, you need to import specific primitives.
This is done to ensure small size of your apps.
Package consists of two parts:
Each curve can be used in the following way:
import { secp256k1 } from '@noble/curves/secp256k1'; // ESM and Common.js
// import { secp256k1 } from 'npm:@noble/curves@1.2.0/secp256k1'; // Deno
const priv = secp256k1.utils.randomPrivateKey();
const pub = secp256k1.getPublicKey(priv);
const msg = new Uint8Array(32).fill(1);
const sig = secp256k1.sign(msg, priv);
const isValid = secp256k1.verify(sig, msg, pub) === true;
// hex strings are also supported besides Uint8Arrays:
const privHex = '46c930bc7bb4db7f55da20798697421b98c4175a52c630294d75a84b9c126236';
const pub2 = secp256k1.getPublicKey(privHex);
All curves:
import { secp256k1, schnorr } from '@noble/curves/secp256k1';
import { ed25519, ed25519ph, ed25519ctx, x25519, RistrettoPoint } from '@noble/curves/ed25519';
import { ed448, ed448ph, ed448ctx, x448 } from '@noble/curves/ed448';
import { p256 } from '@noble/curves/p256';
import { p384 } from '@noble/curves/p384';
import { p521 } from '@noble/curves/p521';
import { pallas, vesta } from '@noble/curves/pasta';
import { bls12_381 } from '@noble/curves/bls12-381';
import { bn254 } from '@noble/curves/bn254';
import { jubjub } from '@noble/curves/jubjub';
Recovering public keys from weierstrass ECDSA signatures; using ECDH:
// extraEntropy https://moderncrypto.org/mail-archive/curves/2017/000925.html
const sigImprovedSecurity = secp256k1.sign(msg, priv, { extraEntropy: true });
sig.recoverPublicKey(msg) === pub; // public key recovery
const someonesPub = secp256k1.getPublicKey(secp256k1.utils.randomPrivateKey());
const shared = secp256k1.getSharedSecret(priv, someonesPub); // ECDH
Schnorr signatures over secp256k1 following BIP340:
import { schnorr } from '@noble/curves/secp256k1';
const priv = schnorr.utils.randomPrivateKey();
const pub = schnorr.getPublicKey(priv);
const msg = new TextEncoder().encode('hello');
const sig = schnorr.sign(msg, priv);
const isValid = schnorr.verify(sig, msg, pub);
ed25519 module has ed25519ctx / ed25519ph variants, x25519 ECDH and ristretto255.
Default verify behavior follows ZIP215 and
can be used in consensus-critical applications.
zip215: false option switches verification criteria to RFC8032 / FIPS 186-5.
import { ed25519 } from '@noble/curves/ed25519';
const priv = ed25519.utils.randomPrivateKey();
const pub = ed25519.getPublicKey(priv);
const msg = new TextEncoder().encode('hello');
const sig = ed25519.sign(msg, priv);
ed25519.verify(sig, msg, pub); // Default mode: follows ZIP215
ed25519.verify(sig, msg, pub, { zip215: false }); // RFC8032 / FIPS 186-5
// Variants from RFC8032: with context, prehashed
import { ed25519ctx, ed25519ph } from '@noble/curves/ed25519';
// ECDH using curve25519 aka x25519
import { x25519 } from '@noble/curves/ed25519';
const priv = 'a546e36bf0527c9d3b16154b82465edd62144c0ac1fc5a18506a2244ba449ac4';
const pub = 'e6db6867583030db3594c1a424b15f7c726624ec26b3353b10a903a6d0ab1c4c';
x25519.getSharedSecret(priv, pub) === x25519.scalarMult(priv, pub); // aliases
x25519.getPublicKey(priv) === x25519.scalarMultBase(priv);
// hash-to-curve
import { hashToCurve, encodeToCurve } from '@noble/curves/ed25519';
import { RistrettoPoint } from '@noble/curves/ed25519';
const rp = RistrettoPoint.fromHex(
'6a493210f7499cd17fecb510ae0cea23a110e8d5b901f8acadd3095c73a3b919'
);
RistrettoPoint.hashToCurve('Ristretto is traditionally a short shot of espresso coffee');
// also has add(), equals(), multiply(), toRawBytes() methods
ed448 is similar:
import { ed448, ed448ph, ed448ctx, x448 } from '@noble/curves/ed448';
import { hashToCurve, encodeToCurve } from '@noble/curves/ed448';
ed448.getPublicKey(ed448.utils.randomPrivateKey());
Every curve has CURVE object that contains its parameters, field, and others:
import { secp256k1 } from '@noble/curves/secp256k1'; // ESM and Common.js
console.log(secp256k1.CURVE.p, secp256k1.CURVE.n, secp256k1.CURVE.a, secp256k1.CURVE.b);
Abstract API allows to define custom curves. All arithmetics is done with JS
bigints over finite fields, which is defined from modular sub-module. For
scalar multiplication, we use
precomputed tables with w-ary non-adjacent form (wNAF).
Precomputes are enabled for weierstrass and edwards BASE points of a curve. You
could precompute any other point (e.g. for ECDH) using utils.precompute()
method: check out examples.
There are following zero-dependency algorithms:
import { weierstrass } from '@noble/curves/abstract/weierstrass';
import { Field } from '@noble/curves/abstract/modular'; // finite field for mod arithmetics
import { sha256 } from '@noble/hashes/sha256'; // 3rd-party sha256() of type utils.CHash
import { hmac } from '@noble/hashes/hmac'; // 3rd-party hmac() that will accept sha256()
import { concatBytes, randomBytes } from '@noble/hashes/utils'; // 3rd-party utilities
const secq256k1 = weierstrass({
// secq256k1: cycle of secp256k1 with Fp/N flipped.
// https://personaelabs.org/posts/spartan-ecdsa
// https://zcash.github.io/halo2/background/curves.html#cycles-of-curves
a: 0n,
b: 7n,
Fp: Field(2n ** 256n - 432420386565659656852420866394968145599n),
n: 2n ** 256n - 2n ** 32n - 2n ** 9n - 2n ** 8n - 2n ** 7n - 2n ** 6n - 2n ** 4n - 1n,
Gx: 55066263022277343669578718895168534326250603453777594175500187360389116729240n,
Gy: 32670510020758816978083085130507043184471273380659243275938904335757337482424n,
hash: sha256,
hmac: (key: Uint8Array, ...msgs: Uint8Array[]) => hmac(sha256, key, concatBytes(...msgs)),
randomBytes,
});
// Replace weierstrass with weierstrassPoints if you don't need ECDSA, hash, hmac, randomBytes
Short Weierstrass curve's formula is y² = x³ + ax + b. weierstrass
expects arguments a, b, field Fp, curve order n, cofactor h
and coordinates Gx, Gy of generator point.
k generation is done deterministically, following
RFC6979. For this you will need
hmac & hash, which in our implementations is provided by noble-hashes. If
you're using different hashing library, make sure to wrap it in the following interface:
type CHash = {
(message: Uint8Array): Uint8Array;
blockLen: number;
outputLen: number;
create(): any;
};
Weierstrass points:
ProjectivePointProjectivePoint.fromHex and ProjectivePoint#toRawBytes()assertValidity() which checks for being on-curvetoAffine() and x / y getters which convert to 2d xy affine coordinates// `weierstrassPoints()` returns `CURVE` and `ProjectivePoint`
// `weierstrass()` returns `CurveFn`
type SignOpts = { lowS?: boolean; prehash?: boolean; extraEntropy: boolean | Uint8Array };
type CurveFn = {
CURVE: ReturnType<typeof validateOpts>;
getPublicKey: (privateKey: PrivKey, isCompressed?: boolean) => Uint8Array;
getSharedSecret: (privateA: PrivKey, publicB: Hex, isCompressed?: boolean) => Uint8Array;
sign: (msgHash: Hex, privKey: PrivKey, opts?: SignOpts) => SignatureType;
verify: (
signature: Hex | SignatureType,
msgHash: Hex,
publicKey: Hex,
opts?: { lowS?: boolean; prehash?: boolean }
) => boolean;
ProjectivePoint: ProjectivePointConstructor;
Signature: SignatureConstructor;
utils: {
normPrivateKeyToScalar: (key: PrivKey) => bigint;
isValidPrivateKey(key: PrivKey): boolean;
randomPrivateKey: () => Uint8Array;
precompute: (windowSize?: number, point?: ProjPointType<bigint>) => ProjPointType<bigint>;
};
};
// T is usually bigint, but can be something else like complex numbers in BLS curves
interface ProjPointType<T> extends Group<ProjPointType<T>> {
readonly px: T;
readonly py: T;
readonly pz: T;
get x(): bigint;
get y(): bigint;
multiply(scalar: bigint): ProjPointType<T>;
multiplyUnsafe(scalar: bigint): ProjPointType<T>;
multiplyAndAddUnsafe(Q: ProjPointType<T>, a: bigint, b: bigint): ProjPointType<T> | undefined;
toAffine(iz?: T): AffinePoint<T>;
isTorsionFree(): boolean;
clearCofactor(): ProjPointType<T>;
assertValidity(): void;
hasEvenY(): boolean;
toRawBytes(isCompressed?: boolean): Uint8Array;
toHex(isCompressed?: boolean): string;
}
// Static methods for 3d XYZ points
interface ProjConstructor<T> extends GroupConstructor<ProjPointType<T>> {
new (x: T, y: T, z: T): ProjPointType<T>;
fromAffine(p: AffinePoint<T>): ProjPointType<T>;
fromHex(hex: Hex): ProjPointType<T>;
fromPrivateKey(privateKey: PrivKey): ProjPointType<T>;
}
ECDSA signatures are represented by Signature instances and can be
described by the interface:
interface SignatureType {
readonly r: bigint;
readonly s: bigint;
readonly recovery?: number;
assertValidity(): void;
addRecoveryBit(recovery: number): SignatureType;
hasHighS(): boolean;
normalizeS(): SignatureType;
recoverPublicKey(msgHash: Hex): ProjPointType<bigint>;
toCompactRawBytes(): Uint8Array;
toCompactHex(): string;
// DER-encoded
toDERRawBytes(): Uint8Array;
toDERHex(): string;
}
type SignatureConstructor = {
new (r: bigint, s: bigint): SignatureType;
fromCompact(hex: Hex): SignatureType;
fromDER(hex: Hex): SignatureType;
};
More examples:
// All curves expose same generic interface.
const priv = secq256k1.utils.randomPrivateKey();
secq256k1.getPublicKey(priv); // Convert private key to public.
const sig = secq256k1.sign(msg, priv); // Sign msg with private key.
secq256k1.verify(sig, msg, priv); // Verify if sig is correct.
const Point = secq256k1.ProjectivePoint;
const point = Point.BASE; // Elliptic curve Point class and BASE point static var.
point.add(point).equals(point.double()); // add(), equals(), double() methods
point.subtract(point).equals(Point.ZERO); // subtract() method, ZERO static var
point.negate(); // Flips point over x/y coordinate.
point.multiply(31415n); // Multiplication of Point by scalar.
point.assertValidity(); // Checks for being on-curve
point.toAffine(); // Converts to 2d affine xy coordinates
secq256k1.CURVE.n;
secq256k1.CURVE.p;
secq256k1.CURVE.Fp.mod();
secq256k1.CURVE.hash();
// precomputes
const fast = secq256k1.utils.precompute(8, Point.fromHex(someonesPubKey));
fast.multiply(privKey); // much faster ECDH now
import { twistedEdwards } from '@noble/curves/abstract/edwards';
import { Field } from '@noble/curves/abstract/modular';
import { sha512 } from '@noble/hashes/sha512';
import { randomBytes } from '@noble/hashes/utils';
const Fp = Field(2n ** 255n - 19n);
const ed25519 = twistedEdwards({
a: Fp.create(-1n),
d: Fp.div(-121665n, 121666n), // -121665n/121666n mod p
Fp: Fp,
n: 2n ** 252n + 27742317777372353535851937790883648493n,
h: 8n,
Gx: 15112221349535400772501151409588531511454012693041857206046113283949847762202n,
Gy: 46316835694926478169428394003475163141307993866256225615783033603165251855960n,
hash: sha512,
randomBytes,
adjustScalarBytes(bytes) {
// optional; but mandatory in ed25519
bytes[0] &= 248;
bytes[31] &= 127;
bytes[31] |= 64;
return bytes;
},
} as const);
Twisted Edwards curve's formula is ax² + y² = 1 + dx²y². You must specify a, d, field Fp, order n, cofactor h
and coordinates Gx, Gy of generator point.
For EdDSA signatures, hash param required. adjustScalarBytes which instructs how to change private scalars could be specified.
Edwards points:
ExtendedPointExtendedPoint.fromHex and ExtendedPoint#toRawBytes()assertValidity() which checks for being on-curvetoAffine() and x / y getters which convert to 2d xy affine coordinatesisTorsionFree(), clearCofactor() and isSmallOrder() utilities to handle torsions// `twistedEdwards()` returns `CurveFn` of following type:
type CurveFn = {
CURVE: ReturnType<typeof validateOpts>;
getPublicKey: (privateKey: Hex) => Uint8Array;
sign: (message: Hex, privateKey: Hex, context?: Hex) => Uint8Array;
verify: (sig: SigType, message: Hex, publicKey: Hex, context?: Hex) => boolean;
ExtendedPoint: ExtPointConstructor;
utils: {
randomPrivateKey: () => Uint8Array;
getExtendedPublicKey: (key: PrivKey) => {
head: Uint8Array;
prefix: Uint8Array;
scalar: bigint;
point: PointType;
pointBytes: Uint8Array;
};
};
};
interface ExtPointType extends Group<ExtPointType> {
readonly ex: bigint;
readonly ey: bigint;
readonly ez: bigint;
readonly et: bigint;
get x(): bigint;
get y(): bigint;
assertValidity(): void;
multiply(scalar: bigint): ExtPointType;
multiplyUnsafe(scalar: bigint): ExtPointType;
isSmallOrder(): boolean;
isTorsionFree(): boolean;
clearCofactor(): ExtPointType;
toAffine(iz?: bigint): AffinePoint<bigint>;
toRawBytes(isCompressed?: boolean): Uint8Array;
toHex(isCompressed?: boolean): string;
}
// Static methods of Extended Point with coordinates in X, Y, Z, T
interface ExtPointConstructor extends GroupConstructor<ExtPointType> {
new (x: bigint, y: bigint, z: bigint, t: bigint): ExtPointType;
fromAffine(p: AffinePoint<bigint>): ExtPointType;
fromHex(hex: Hex): ExtPointType;
fromPrivateKey(privateKey: Hex): ExtPointType;
}
import { montgomery } from '@noble/curves/abstract/montgomery';
import { Field } from '@noble/curves/abstract/modular';
const x25519 = montgomery({
a: 486662n,
Gu: 9n,
Fp: Field(2n ** 255n - 19n),
montgomeryBits: 255,
nByteLength: 32,
// Optional param
adjustScalarBytes(bytes) {
bytes[0] &= 248;
bytes[31] &= 127;
bytes[31] |= 64;
return bytes;
},
});
The module contains methods for x-only ECDH on Curve25519 / Curve448 from RFC7748. Proper Elliptic Curve Points are not implemented yet.
You must specify curve params Fp, a, Gu coordinate of u, montgomeryBits and nByteLength.
The module abstracts BLS (Barreto-Lynn-Scott) pairing-friendly elliptic curve construction. They allow to construct zk-SNARKs and use aggregated, batch-verifiable threshold signatures, using Boneh-Lynn-Shacham signature scheme.
Main methods and properties are:
getPublicKey(privateKey)sign(message, privateKey)verify(signature, message, publicKey)aggregatePublicKeys(publicKeys)aggregateSignatures(signatures)G1 and G2 curves containing CURVE and ProjectivePointSignature property with fromHex, toHex methodsfields containing Fp, Fp2, Fp6, Fp12, FrRight now we only implement BLS12-381 (compatible with ETH and others), but in theory defining BLS12-377, BLS24 should be straightforward. An example:
import { bls12_381 as bls } from '@noble/curves/bls12-381';
const privateKey = '67d53f170b908cabb9eb326c3c337762d59289a8fec79f7bc9254b584b73265c';
const message = '64726e3da8';
const publicKey = bls.getPublicKey(privateKey);
const signature = bls.sign(message, privateKey);
const isValid = bls.verify(signature, message, publicKey);
console.log({ publicKey, signature, isValid });
// Sign 1 msg with 3 keys
const privateKeys = [
'18f020b98eb798752a50ed0563b079c125b0db5dd0b1060d1c1b47d4a193e1e4',
'ed69a8c50cf8c9836be3b67c7eeff416612d45ba39a5c099d48fa668bf558c9c',
'16ae669f3be7a2121e17d0c68c05a8f3d6bef21ec0f2315f1d7aec12484e4cf5',
];
const messages = ['d2', '0d98', '05caf3'];
const publicKeys = privateKeys.map(bls.getPublicKey);
const signatures2 = privateKeys.map((p) => bls.sign(message, p));
const aggPubKey2 = bls.aggregatePublicKeys(publicKeys);
const aggSignature2 = bls.aggregateSignatures(signatures2);
const isValid2 = bls.verify(aggSignature2, message, aggPubKey2);
console.log({ signatures2, aggSignature2, isValid2 });
// Sign 3 msgs with 3 keys
const signatures3 = privateKeys.map((p, i) => bls.sign(messages[i], p));
const aggSignature3 = bls.aggregateSignatures(signatures3);
const isValid3 = bls.verifyBatch(aggSignature3, messages, publicKeys);
console.log({ publicKeys, signatures3, aggSignature3, isValid3 });
// bls.pairing(PointG1, PointG2) // pairings
// bls.G1.ProjectivePoint.BASE, bls.G2.ProjectivePoint.BASE
// bls.fields.Fp, bls.fields.Fp2, bls.fields.Fp12, bls.fields.Fr
// hash-to-curve examples can be seen below
Full types:
getPublicKey: (privateKey: PrivKey) => Uint8Array;
sign: {
(message: Hex, privateKey: PrivKey): Uint8Array;
(message: ProjPointType<Fp2>, privateKey: PrivKey): ProjPointType<Fp2>;
};
verify: (
signature: Hex | ProjPointType<Fp2>,
message: Hex | ProjPointType<Fp2>,
publicKey: Hex | ProjPointType<Fp>
) => boolean;
verifyBatch: (
signature: Hex | ProjPointType<Fp2>,
messages: (Hex | ProjPointType<Fp2>)[],
publicKeys: (Hex | ProjPointType<Fp>)[]
) => boolean;
aggregatePublicKeys: {
(publicKeys: Hex[]): Uint8Array;
(publicKeys: ProjPointType<Fp>[]): ProjPointType<Fp>;
};
aggregateSignatures: {
(signatures: Hex[]): Uint8Array;
(signatures: ProjPointType<Fp2>[]): ProjPointType<Fp2>;
};
millerLoop: (ell: [Fp2, Fp2, Fp2][], g1: [Fp, Fp]) => Fp12;
pairing: (P: ProjPointType<Fp>, Q: ProjPointType<Fp2>, withFinalExponent?: boolean) => Fp12;
G1: CurvePointsRes<Fp> & ReturnType<typeof htf.createHasher<Fp>>;
G2: CurvePointsRes<Fp2> & ReturnType<typeof htf.createHasher<Fp2>>;
Signature: SignatureCoder<Fp2>;
params: {
x: bigint;
r: bigint;
G1b: bigint;
G2b: Fp2;
};
fields: {
Fp: IField<Fp>;
Fp2: IField<Fp2>;
Fp6: IField<Fp6>;
Fp12: IField<Fp12>;
Fr: IField<bigint>;
};
utils: {
randomPrivateKey: () => Uint8Array;
calcPairingPrecomputes: (p: AffinePoint<Fp2>) => [Fp2, Fp2, Fp2][];
};
The module allows to hash arbitrary strings to elliptic curve points. Implements hash-to-curve v16.
Every curve has exported hashToCurve and encodeToCurve methods. You should always prefer hashToCurve for security:
import { hashToCurve, encodeToCurve } from '@noble/curves/secp256k1';
import { randomBytes } from '@noble/hashes/utils';
hashToCurve('0102abcd');
console.log(hashToCurve(randomBytes()));
console.log(encodeToCurve(randomBytes()));
import { bls12_381 } from '@noble/curves/bls12-381';
bls12_381.G1.hashToCurve(randomBytes(), { DST: 'another' });
bls12_381.G2.hashToCurve(randomBytes(), { DST: 'custom' });
If you need low-level methods from spec:
expand_message_xmd (spec) produces a uniformly random byte string using a cryptographic hash function H that outputs b bits.
Hash must conform to CHash interface (see weierstrass section).
function expand_message_xmd(
msg: Uint8Array,
DST: Uint8Array,
lenInBytes: number,
H: CHash
): Uint8Array;
function expand_message_xof(
msg: Uint8Array,
DST: Uint8Array,
lenInBytes: number,
k: number,
H: CHash
): Uint8Array;
hash_to_field(msg, count, options)
(spec)
hashes arbitrary-length byte strings to a list of one or more elements of a finite field F.
/**
* * `DST` is a domain separation tag, defined in section 2.2.5
* * `p` characteristic of F, where F is a finite field of characteristic p and order q = p^m
* * `m` is extension degree (1 for prime fields)
* * `k` is the target security target in bits (e.g. 128), from section 5.1
* * `expand` is `xmd` (SHA2, SHA3, BLAKE) or `xof` (SHAKE, BLAKE-XOF)
* * `hash` conforming to `utils.CHash` interface, with `outputLen` / `blockLen` props
*/
type UnicodeOrBytes = string | Uint8Array;
type Opts = {
DST: UnicodeOrBytes;
p: bigint;
m: number;
k: number;
expand?: 'xmd' | 'xof';
hash: CHash;
};
/**
* Hashes arbitrary-length byte strings to a list of one or more elements of a finite field F
* https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-hash-to-curve-11#section-5.3
* @param msg a byte string containing the message to hash
* @param count the number of elements of F to output
* @param options `{DST: string, p: bigint, m: number, k: number, expand: 'xmd' | 'xof', hash: H}`, see above
* @returns [u_0, ..., u_(count - 1)], a list of field elements.
*/
function hash_to_field(msg: Uint8Array, count: number, options: Opts): bigint[][];
Implements Poseidon ZK-friendly hash.
There are many poseidon variants with different constants. We don't provide them: you should construct them manually. Check out micro-starknet package for a proper example.
import { poseidon } from '@noble/curves/abstract/poseidon';
type PoseidonOpts = {
Fp: Field<bigint>;
t: number;
roundsFull: number;
roundsPartial: number;
sboxPower?: number;
reversePartialPowIdx?: boolean;
mds: bigint[][];
roundConstants: bigint[][];
};
const instance = poseidon(opts: PoseidonOpts);
import * as mod from '@noble/curves/abstract/modular';
const fp = mod.Field(2n ** 255n - 19n); // Finite field over 2^255-19
fp.mul(591n, 932n); // multiplication
fp.pow(481n, 11024858120n); // exponentiation
fp.div(5n, 17n); // division: 5/17 mod 2^255-19 == 5 * invert(17)
fp.sqrt(21n); // square root
// Generic non-FP utils are also available
mod.mod(21n, 10n); // 21 mod 10 == 1n; fixed version of 21 % 10
mod.invert(17n, 10n); // invert(17) mod 10; modular multiplicative inverse
mod.invertBatch([1n, 2n, 4n], 21n); // => [1n, 11n, 16n] in one inversion
Suppose you have sha256(something) (e.g. from HMAC) and you want to make a private key from it.
Even though p256 or secp256k1 may have 32-byte private keys,
and sha256 output is also 32-byte, you can't just use it and reduce it modulo CURVE.n.
Doing so will make the result key biased.
To avoid the bias, we implement FIPS 186 B.4.1, which allows to take arbitrary byte array and produce valid scalars / private keys with bias being neglible.
Use hash-to-curve if you need hashing to public keys; the function in the module instead operates on private keys.
import { p256 } from '@noble/curves/p256';
import { sha256 } from '@noble/hashes/sha256';
import { hkdf } from '@noble/hashes/hkdf';
const someKey = new Uint8Array(32).fill(2); // Needs to actually be random, not .fill(2)
const derived = hkdf(sha256, someKey, undefined, 'application', 40); // 40 bytes
const validPrivateKey = mod.hashToPrivateScalar(derived, p256.CURVE.n);
import * as utils from '@noble/curves/abstract/utils';
utils.bytesToHex(Uint8Array.from([0xde, 0xad, 0xbe, 0xef]));
utils.hexToBytes('deadbeef');
utils.numberToHexUnpadded(123n);
utils.hexToNumber();
utils.bytesToNumberBE(Uint8Array.from([0xde, 0xad, 0xbe, 0xef]));
utils.bytesToNumberLE(Uint8Array.from([0xde, 0xad, 0xbe, 0xef]));
utils.numberToBytesBE(123n, 32);
utils.numberToBytesLE(123n, 64);
utils.concatBytes(Uint8Array.from([0xde, 0xad]), Uint8Array.from([0xbe, 0xef]));
utils.nLength(255n);
utils.equalBytes(Uint8Array.from([0xde]), Uint8Array.from([0xde]));
curve, hash-to-curve, modular, poseidon, utils, weierstrass, and top-level modules _shortw_utils and secp256k1. See changes since audit.We consider infrastructure attacks like rogue NPM modules very important; that's why it's crucial to minimize the amount of 3rd-party dependencies & native bindings. If your app uses 500 dependencies, any dep could get hacked and you'll be downloading malware with every npm install. Our goal is to minimize this attack vector. As for devDependencies used by the library:
@scure base, bip32, bip39 (used in tests), micro-bmark (benchmark), micro-should (testing) are developed by us
and follow the same practices such as: minimal library size, auditability, signed releasesnpm-diff.
The packages are big, which makes it hard to audit their source code thoroughly and fully.Benchmark results on Apple M2 with node v19:
secp256k1
init x 58 ops/sec @ 17ms/op
getPublicKey x 5,640 ops/sec @ 177μs/op
sign x 4,471 ops/sec @ 223μs/op
verify x 780 ops/sec @ 1ms/op
getSharedSecret x 465 ops/sec @ 2ms/op
recoverPublicKey x 740 ops/sec @ 1ms/op
schnorr.sign x 597 ops/sec @ 1ms/op
schnorr.verify x 775 ops/sec @ 1ms/op
P256
init x 31 ops/sec @ 31ms/op
getPublicKey x 5,607 ops/sec @ 178μs/op
sign x 4,583 ops/sec @ 218μs/op
verify x 540 ops/sec @ 1ms/op
P384
init x 15 ops/sec @ 63ms/op
getPublicKey x 2,622 ops/sec @ 381μs/op
sign x 2,106 ops/sec @ 474μs/op
verify x 222 ops/sec @ 4ms/op
P521
init x 8 ops/sec @ 119ms/op
getPublicKey x 1,371 ops/sec @ 729μs/op
sign x 1,164 ops/sec @ 858μs/op
verify x 118 ops/sec @ 8ms/op
ed25519
init x 47 ops/sec @ 20ms/op
getPublicKey x 9,414 ops/sec @ 106μs/op
sign x 4,516 ops/sec @ 221μs/op
verify x 912 ops/sec @ 1ms/op
ed448
init x 17 ops/sec @ 56ms/op
getPublicKey x 3,363 ops/sec @ 297μs/op
sign x 1,615 ops/sec @ 619μs/op
verify x 319 ops/sec @ 3ms/op
ecdh
├─x25519 x 1,337 ops/sec @ 747μs/op
├─secp256k1 x 461 ops/sec @ 2ms/op
├─P256 x 441 ops/sec @ 2ms/op
├─P384 x 179 ops/sec @ 5ms/op
├─P521 x 93 ops/sec @ 10ms/op
└─x448 x 496 ops/sec @ 2ms/op
bls12-381
init x 32 ops/sec @ 30ms/op
getPublicKey 1-bit x 858 ops/sec @ 1ms/op
getPublicKey x 858 ops/sec @ 1ms/op
sign x 49 ops/sec @ 20ms/op
verify x 34 ops/sec @ 28ms/op
pairing x 94 ops/sec @ 10ms/op
aggregatePublicKeys/8 x 116 ops/sec @ 8ms/op
aggregatePublicKeys/32 x 31 ops/sec @ 31ms/op
aggregatePublicKeys/128 x 7 ops/sec @ 125ms/op
aggregateSignatures/8 x 45 ops/sec @ 22ms/op
aggregateSignatures/32 x 11 ops/sec @ 84ms/op
aggregateSignatures/128 x 3 ops/sec @ 332ms/opp
hash-to-curve
hash_to_field x 850,340 ops/sec @ 1μs/op
secp256k1 x 2,143 ops/sec @ 466μs/op
P256 x 3,861 ops/sec @ 258μs/op
P384 x 1,526 ops/sec @ 655μs/op
P521 x 748 ops/sec @ 1ms/op
ed25519 x 2,772 ops/sec @ 360μs/op
ed448 x 1,146 ops/sec @ 871μs/op
npm install to install build dependencies like TypeScriptnpm run build to compile TypeScript codenpm run test will execute all main testsPreviously, the library was split into single-feature packages noble-secp256k1 and noble-ed25519. curves can be thought as a continuation of their original work. The libraries now changed their direction towards providing minimal 4kb implementations of cryptography and are not as feature-complete.
Upgrading from @noble/secp256k1 2.0 or @noble/ed25519 2.0: no changes, libraries are compatible.
Upgrading from @noble/secp256k1 1.7:
getPublicKey
isCompressed to false: getPublicKey(priv, false)sign
signAsync for async versionSignature instance with { r, s, recovery } propertiescanonical option was renamed to lowSrecovered option has been removed because recovery bit is always returned nowder option has been removed. There are 2 options:
fromCompact, toCompactRawBytes, toCompactHex.
Compact encoding is simply a concatenation of 32-byte r and 32-byte s.verify
strict option was renamed to lowSgetSharedSecret
isCompressed to false: getSharedSecret(a, b, false)recoverPublicKey(msg, sig, rec) was changed to sig.recoverPublicKey(msg)number type for private keys have been removed: use bigint insteadPoint (2d xy) has been changed to ProjectivePoint (3d xyz)utils were split into utils (same api as in noble-curves) and
etc (hmacSha256Sync and others)Upgrading from @noble/ed25519 1.7:
bigint is no longer allowed in getPublicKey, sign, verify. Reason: ed25519 is LE, can lead to bugsPoint (2d xy) has been changed to ExtendedPoint (xyzt)Signature was removed: just use raw bytes or hex nowutils were split into utils (same api as in noble-curves) and
etc (sha512Sync and others)getSharedSecret was moved to x25519 moduleUpgrading from @noble/bls12-381:
Useful articles about the library or its primitives:
Real-world software that uses curves:
The MIT License (MIT)
Copyright (c) 2022 Paul Miller (https://paulmillr.com)
See LICENSE file.
FAQs
Audited & minimal JS implementation of elliptic curve cryptography
The npm package @noble/curves receives a total of 2,225,617 weekly downloads. As such, @noble/curves popularity was classified as popular.
We found that @noble/curves demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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