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

npm install

Building

npm run build

Testing

The project includes comprehensive test coverage for all cryptographic operations:

Running Tests

# Run tests in watch mode
npm test

# Run tests once
npm run test:run

# Run tests with coverage
npm run test:coverage

Test Coverage

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

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