@hyperbitjs/eckey

Elliptic Curve cryptography library for managing private/public keys in Node.js and the browser. Used with cryptocurrencies such as Bitcoin, Litecoin, Dogecoin, and many others.

Features

• Dual module support: Works with both CommonJS (.cjs) and ES modules (.mjs)
• Full TypeScript support: Includes complete type definitions
• Key management: Create, import, and manage EC keys
• Cryptographic operations: Sign messages with private keys and verify signatures
• Hash operations: SHA256 and RIPEMD160 hashing support
• Compression: Support for compressed and uncompressed public keys
• Cross-platform: Node.js and browser compatible

Installation

npm install @hyperbitjs/eckey

Quick Start

import { ECKey } from '@hyperbitjs/eckey';

// Create a new key pair
const key = new ECKey();

// Access the keys
const privateKey = key.privateKey; // Buffer
const publicKey = key.publicKey; // Buffer (compressed by default)
const publicKeyHash = key.pubKeyHash; // Buffer - RIPEMD160(SHA256(publicKey))

// Import from existing private key
const importedKey = new ECKey(privateKeyBuffer, compressed);

// Sign a message
const signature = key.sign(message);

// Verify a signature
const isValid = key.verify(message, signature);

API Reference

ECKey Class

Constructor

constructor(bytes?: KeyInput, compressed?: boolean)

• bytes?: KeyInput - Private key bytes (Buffer, Uint8Array, or Array). Optional.
• compressed?: boolean - Whether public key should be compressed (default: true)

Properties

• privateKey: Buffer - Get/set the private key (32 bytes)
• privateExportKey: Buffer - Get the private key in export format
• publicKey: Buffer - Get the public key (33 or 65 bytes depending on compression)
• pubKeyHash: Buffer - Get the public key hash (20 bytes)
• publicHash: Buffer - Alias for pubKeyHash

Methods

• sign(message: Buffer): Buffer - Sign a message with the private key
• verify(message: Buffer, signature: Buffer): boolean - Verify a message signature
• getPublicKey(compressed?: boolean): Buffer - Get the public key in specified format

Usage Examples

Basic Key Generation

import { ECKey } from '@hyperbitjs/eckey';

// Create a random key
const key = new ECKey();
console.log(key.publicKey); // 33-byte compressed public key
console.log(key.pubKeyHash); // 20-byte hash

Working with Existing Keys

// Import from WIF (Wallet Import Format) or hex
const hexPrivateKey = Buffer.from('1234567890abcdef...', 'hex');
const key = new ECKey(hexPrivateKey, true); // true for compression

// Export formats
console.log(key.privateKey); // Raw 32-byte private key
console.log(key.privateExportKey); // Private key + compression flag

Message Signing

import { createHash } from 'crypto';

const key = new ECKey();
const message = Buffer.from('Hello, Bitcoin!');

// In real applications, use proper message hashing
const messageHash = createHash('sha256').update(message).digest();

const signature = key.sign(messageHash);
const isValid = key.verify(messageHash, signature);

console.log('Signature valid:', isValid);

Type Definitions

Full TypeScript interfaces are provided:

export type KeyInput = Buffer | Uint8Array | Array<number>;

export interface IECKey {
  privateKey: Buffer;
  privateExportKey: Buffer;
  publicKey: Buffer;
  pubKeyHash: Buffer;
  publicHash: Buffer;
  sign(message: Buffer): Buffer;
  verify(message: Buffer, signature: Buffer): boolean;
  getPublicKey(compressed?: boolean): Buffer;
}

Browser Compatibility

This library works in modern browsers with ES module support. Use a bundler like Webpack, Vite, or Rollup for production builds.

<script type="module">
  import { ECKey } from 'https://cdn.jsdelivr.net/npm/@hyperbitjs/eckey/dist/index.mjs';

  const key = new ECKey();
  console.log(key.publicKey);
</script>

Security Notes

• Private key handling: Always keep private keys secure and never share them
• Message hashing: Always properly hash messages before signing
• Key storage: Consider using encrypted storage for sensitive applications
• Entropy: This library uses Node.js's built-in crypto for key generation

Contributing

Contributions are welcome! Please read our CONTRIBUTING guide first.

Development

# Install dependencies
npm install

# Run tests
npm run test

# Type checking
npm run type-check

# Linting
npm run lint

# Build
npm run build

# Format code
npm run format

License

MIT © Hyperbit

Related Projects

• @hyperbitjs/hdkey - BIP32 HD key derivation
• @hyperbitjs/chains - Blockchain network definitions
• @hyperbitjs/mnemonic - BIP39 mnemonic support

Support

For issues, questions, or suggestions:

• Open an issue on GitHub
• Check existing documentation and examples
• Review our CHANGELOG for version history

Overview

This project lives at eckey and is part of the broader multi-project workspace. Description: Handle private key and public keys associated with elliptic curve cryptography. Used with crypto currencies such as Bitcoin, Litecoin, Dogecoin, etc. Works in both Node.js and the browser.

Purpose

• Deliver the core capability owned by this project.
• Provide stable commands and interfaces for other apps/packages in the workspace.
• Keep implementation details localized so changes stay maintainable.

Architecture Notes

• Type: Project
• Package manager metadata source: package.json
• Runtime entry hints: ./dist/index.cjs

Setup

1. Install dependencies from this directory:

npm install

2. Run key scripts as needed (see script table below).

NPM Scripts

Script	Command
build	vite build
build:watch	vite build --watch
dev	vite build --watch
type-check	tsc --noEmit
lint	eslint . --max-warnings 0
lint:fix	eslint . --fix
format	prettier --write .
format:check	prettier --check .
test	vitest --run
test:watch	vitest
test:coverage	vitest --coverage
validate	npm run type-check && npm run lint && npm run test
prepublishOnly	npm run build && npm run validate

Dependencies

Production

• secp256k1: ^5.0.1

Development

• @types/node: ^20.10.0
• @typescript-eslint/eslint-plugin: ^6.21.0
• @typescript-eslint/parser: ^6.21.0
• @vitest/coverage-v8: ^1.1.0
• eslint: ^8.56.0
• prettier: ^3.0.3
• secure-random: ^1.1.1
• typescript: ^5.3.3
• vite: ^5.0.11
• vitest: ^1.1.3

Configuration

• Primary config source: package.json
• No .env.example detected in this directory.
• Add project-specific operational notes to MEMORY_BANK.md.

Development Workflow

1. Make changes in focused modules.
2. Run the smallest relevant script/test first.
3. Run full validation scripts before merging.
4. Update this README and memory bank whenever behavior/contracts change.

Testing and Validation

• Prefer script-driven checks from the table above (for example: test, build, lint).
• If this project has no tests yet, add smoke checks and document them in MEMORY_BANK.md.

LLM Context

When using an LLM coding assistant in this folder, always include:

• Exact target file paths and expected behavior changes.
• Validation command(s) run after edits.
• Runtime/config assumptions (.env, API keys, ports, external services).

Memory Bank

See MEMORY_BANK.md for operational context, commands, and troubleshooting notes.