Octopus TypeScript SDK

This TypeScript SDK provides cryptographic operations for the Aptos crypto oracle, including ElGamal encryption over BLS12-381 curves with AES-256-GCM for symmetric encryption.

Features

- ElGamal Encryption: Public-key encryption over BLS12-381 elliptic curves
- AES-256-GCM: Authenticated symmetric encryption for bulk data
- Hybrid Encryption: Combines asymmetric and symmetric encryption for efficiency
- TypeScript Support: Full TypeScript support with proper type definitions
- Serialization: Support for Aptos Move serialization format

Installation

``bash
npm install
`

Building

`bash
npm run build
`

Testing

The project includes comprehensive test coverage for all cryptographic operations:

$3

`bash


Run tests in watch mode

npm test

Run tests once

npm run test:run

Run tests with coverage

npm run test:coverage
`

$3

The test suite covers:

1. Key Generation
- Valid key pair generation
- Uniqueness of generated keys
- BLS12-381 curve point validation

2. Encryption & Decryption
- Basic encryption/decryption functionality
- Empty and large plaintext handling
- Binary data support
- Unicode text support
- Wrong key rejection

3. Serialization
- Byte array serialization/deserialization
- Hex encoding/decoding
- Key integrity preservation

4. Error Handling
- Corrupted ciphertext handling
- Truncated data handling
- Invalid input validation

5. Cryptographic Properties
- Semantic security verification
- Key privacy validation
- Multiple encryption support

6. Performance & Edge Cases
- Multiple key generation efficiency
- Large data handling
- Boundary condition testing

Usage

`typescript
import { keygen, encrypt, tryDecrypt } from './src/elgamal_bls12381_aes256gcm';

// Generate key pair
const { privateKey, publicKey } = keygen();

// Encrypt data
const plaintext = new TextEncoder().encode('Hello, World!');
const ciphertext = encrypt(publicKey, plaintext);

// Decrypt data
const decrypted = tryDecrypt(privateKey, ciphertext);
console.log(new TextDecoder().decode(decrypted)); // "Hello, World!"
`

Dependencies

- @aptos-labs/ts-sdk: Aptos TypeScript SDK for serialization
- @noble/curves: BLS12-381 elliptic curve implementation
- @noble/hashes: SHA-256 hash function
- crypto`: Node.js built-in cryptographic functions

Security

This implementation provides:
- Semantic Security: Same plaintext produces different ciphertexts
- Key Privacy: Ciphertexts don't reveal the public key
- Authenticated Encryption: AES-GCM provides both confidentiality and authenticity
- Post-Quantum Resistance: BLS12-381 curves provide quantum resistance