@shadowpay/core

Core cryptographic utilities for the ShadowPay SDK. Provides zero-knowledge proof primitives, ElGamal encryption, Poseidon hashing, and commitment generation for private payments on Solana.

Installation

npm install @shadowpay/core

Features

• ElGamal Encryption - Encrypt payment amounts on BN254 curve
• Poseidon Hashing - Generate cryptographic commitments and nullifiers
• Commitment Generation - Create sender and payment commitments
• Field Element Operations - Convert Solana addresses to BN254 field elements
• Token Utilities - Parse amounts for SOL, USDC, and USDT

Usage

ElGamal Encryption

import { generateElGamalKeypair, encryptAmount } from '@shadowpay/core';

const keypair = generateElGamalKeypair();
const encrypted = encryptAmount(1000000n, keypair.publicKey);

console.log(encrypted.c1); // Ciphertext component 1
console.log(encrypted.c2); // Ciphertext component 2

Generate Commitments

import {
  generateRandomSecret,
  generateRandomSalt,
  computeSenderCommitment,
  computePaymentCommitment,
} from '@shadowpay/core';

const secret = generateRandomSecret();
const salt = generateRandomSalt();

const senderCommitment = await computeSenderCommitment(
  'YourWalletAddressHere',
  secret
);

const paymentCommitment = await computePaymentCommitment(
  senderCommitment,
  receiverCommitment,
  1000000n,
  'SOL',
  salt
);

Token Utilities

import { parseAmount, TOKENS } from '@shadowpay/core';

const lamports = parseAmount(0.001, 'SOL'); // 1000000
const usdcAmount = parseAmount(10, 'USDC'); // 10000000

API Reference

Encryption

• generateElGamalKeypair() - Generate ElGamal keypair
• encryptAmount(amount, publicKey) - Encrypt an amount

Commitments

• generateRandomSecret() - Generate random secret (32 bytes)
• generateRandomSalt() - Generate random salt (32 bytes)
• computeSenderCommitment(walletPubkey, secret) - Generate sender commitment
• computePaymentCommitment(sender, receiver, amount, token, salt) - Generate payment commitment
• computePaymentNullifier(secret, commitment) - Generate nullifier
• addressToFieldElement(address) - Convert Solana address to field element

Tokens

• parseAmount(amount, token) - Convert human-readable amount to lamports
• TOKENS - Token configuration (SOL, USDC, USDT)

Constants

export const API_URL = 'https://shadow.radr.fun';
export const CIRCUIT_URLS = {
  wasm: 'https://shadow.radr.fun/shadowpay/circuit-elgamal/...',
  zkey: 'https://shadow.radr.fun/shadowpay/circuit-elgamal/...',
  vkey: 'https://shadow.radr.fun/shadowpay/circuit-elgamal/...',
};

License

MIT