# supercop > cross-compiled javascript implementation of ed25519 based on supercop-ref10 Latest version **3.0.3** (published 2026-03-14) · MIT license · 0 weekly downloads ## Install ```sh npm install supercop pnpm add supercop yarn add supercop bun add supercop ``` ## Health **Score 65/100 (B)** — status: stable. Positive: has types; esm support; no vulnerabilities; has provenance; high quality score. Warnings: low downloads. ## Facts | | | |---|---| | Version | 3.0.3 | | Published | 2026-03-14 | | First published | 2019-06-19 | | Weekly downloads | 0 | | License | MIT | | TypeScript types | bundled | | Module format | ESM + CommonJS | | Dependencies | 0 | | Unpacked size | 198.5 KB | | Known vulnerabilities | 0 | | Install scripts | no | | Provenance | attested (GitHub Actions) | | GitHub stars | 1 | | Author | Yersa Nordman | | Maintainers | finwo | | Keywords | ed25519, supercop, ref10, elliptic, curve, webassembly | ## Links - npm: https://www.npmjs.com/package/supercop - Repository: https://github.com/finwo/supercop - Issues: https://github.com/finwo/supercop/issues - Funding: https://github.com/sponsors/finwo - npm.io page: https://npm.io/package/supercop ## Alternatives - [jsforce](https://npm.io/package/jsforce.md) — 851.2K weekly downloads - [react-native-qrcode-svg](https://npm.io/package/react-native-qrcode-svg.md) — 693.5K weekly downloads - [@salesforce/plugin-data](https://npm.io/package/@salesforce/plugin-data.md) — 394.9K weekly downloads - [@backstage/plugin-search-common](https://npm.io/package/@backstage/plugin-search-common.md) — 308.5K weekly downloads - [@chain-registry/types](https://npm.io/package/@chain-registry/types.md) — 38.4K weekly downloads ## Recent versions - 3.0.3 (latest) — 2026-03-14 - 3.0.2 — 2024-05-23 - 3.0.1 — 2023-06-09 - 3.0.0 — 2023-05-30 - 2.2.6 — 2023-04-03 - 2.2.5 — 2021-08-25 - 2.2.4 — 2021-08-22 - 2.2.3 — 2021-08-18 - 2.2.2 — 2021-06-18 - 2.2.1 — 2021-02-17 - 2.2.0 — 2021-02-17 - 2.1.3 — 2020-08-10 - 2.1.2 — 2020-08-10 - 2.1.1 — 2020-08-10 - 2.1.0 — 2020-08-09 - … 26 more at https://npm.io/package/supercop/versions ## README # supercop ed25519 curve operations using [orlp/ed25519](https://github.com/orlp/ed25519) patched and compiled into WebAssembly. ## TL;DR; For when you don't want to dig through the whole API reference ```typescript import { createSeed, KeyPair } from 'supercop'; // Create keypairs, usable for keyExchange, signing and verifying const alice = await KeyPair.create(createSeed()); const bob = await KeyPair.create(createSeed()); const charlie = await KeyPair.from(JSON.parse(fs.readFileSync('path-to-file.json'))); // Save bob's key, will become charlie's key in the next run fs.writeFileSync('path-to-file.json', JSON.stringify(bob)); // Public-only keypairs are possible, usable only for: // - Verifying a signature // - Remote side of key exchange const alicePub = KeyPair.from({ publicKey: alice.publicKey }); const bobPub = KeyPair.from({ publicKey: bob.publicKey }); const message = "Hello World!"; // Alice signing the message with her key const signature = await alice.sign(message); // Bob verifying the message came from alice const isValid = await alicePub.verify(signature, message); console.log({ isValid }); // outputs true // Generate shared keys on both ends const aliceShared = await alice.keyExchange(bobPub); const bobShared = await bob.keyExchange(alicePub); // Proof both keys are the same console.log(Buffer.compare(aliceShared, bobShared) == 0); // outputs true ``` ## About This package provides ed25519/ref10 operations from orlp's implementation into JavaScript/TypeScript in an unopiniated way. The patching applied is so we can compile it with without relying on emscriptem, but instead go purely for [clang](https://clang.llvm.org/). ## API reference / exports ### type PublicKey: Buffer Represents a public key in a keypair, simply a 32-byte buffer ### type SecretKey: Buffer Represents a secret key in a keypair, simply a 64-byte buffer ### type Seed: Buffer Represents a seed to build a keypair from, simply a 32-byte buffer ### type Signature: Buffer Represents a signature you can use to verify a message, simply a 64-byte buffer ### function isSeed(data: unknown): data is Seed Returns whether or not a piece of data can be used as a seed ### function isPublicKey(data: unknown): data is PublicKey Returns whether or not a piece of data can be used as a public key ### function isSignature(data: unknown): data is Signature Returns whether or not a piece of data can be used as a signature ### function isSecretKey(data: unknown): data is SecretKey Returns whether or not a piece of data can be used as a secret key ### function createSeed(): Buffer Uses `Math.random` to generate a new key. Only use this as a last resort, as `crypto.randomBytes(32)` provides better randomization. ### function createKeyPair(seed: number[] | Seed): Promise<KeyPair> Build a new KeyPair instance from the given seed. ### function keyPairFrom({ publicKey: number[] | PublicKey, secretKey?: number[] | SecretKey }): KeyPair Constructs a new KeyPair instance from the key(s) provided you can use to operate with. ### function sign(message: string | Buffer, publicKey: number[] | PublicKey, secretKey: number[] | SecretKey): Promise<Signature> Sign a message with the given keys, so it can be verified later ### function verify(signature: number[] | Signature, message: string | Buffer, publicKey: number[] | PublicKey): Promise<boolean> Verify a message/signature combination using the given public key ### function keyExchange(theirPublicKey: number[] | PublicKey | undefined, ourSecretKey: number[] | SecretKey): Promise<Buffer> Generate a shared secret between 2 key pairs to use as seed for a symmetric encryption algorithm ### class KeyPair ```typescript class KeyPair { // Calls the sign function with the keys stored in the entity sign(message: string | Buffer): Promise; // Calls the verify function with the keys stored in the entity verify(signature: number[] | Signature, message: string | Buffer): Promise; // Performs key exchange algorithm between the local key and the given key // Assumes the local key is 'our' key keyExchange(theirPublicKey?: number[] | PublicKey): Promise; // Converts the key into something storable to be reconstructed in a later run toJSON(): { publicKey: number[] | undefined; secretKey: number[] | undefined; }; // Generate a (new) keypair from the given seed static create(seed: number[] | Seed): Promise; // Reconstruct a keypair from the given data, compatible with the toJSON output format static from(data: { publicKey: number[] | PublicKey; secretKey?: number[] | SecretKey; }): KeyPair; } ``` --- _Source: https://npm.io/package/supercop · Machine-readable twin of the npm.io package page. 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