lamport/sdk/README.md

@luxfi/lamport

Quantum-resistant Lamport One-Time Signatures for EVM smart contracts.

Features

• 🔐 Quantum-resistant - Uses only keccak256, secure against Grover's algorithm
• ⚡ Gas-optimized - Assembly verification at 164K gas (7.5x improvement)
• 🔒 Constant-time - Side-channel resistant verification variant
• 🏦 Safe integration - Gnosis Safe module with atomic key rotation
• 🤝 Threshold support - T-of-N MPC coordination for distributed signing
• 📦 TypeScript SDK - Complete key generation, signing, and verification

Installation

# npm
npm install @luxfi/lamport viem

# pnpm
pnpm add @luxfi/lamport viem

# yarn
yarn add @luxfi/lamport viem

Quick Start

Key Generation

import { generateKeyPair, generateKeyChain } from '@luxfi/lamport'

// Generate a single key pair
const keyPair = generateKeyPair()
console.log('PKH:', keyPair.pkh)

// Generate a key chain (100 pre-generated keys)
const keyChain = generateKeyChain(100)

Signing

import { sign, signWithRotation, keccak256, toBytes } from '@luxfi/lamport'

// Sign a message
const message = keccak256(toBytes('Hello, Quantum World!'))
const signature = sign(message, keyPair.privateKey)

// Sign with key rotation (recommended)
const { signature, nextPKH } = signWithRotation(
  message,
  currentKeyPair,
  nextKeyPair
)

Verification

import { verify, computePKH } from '@luxfi/lamport'

// Off-chain verification
const valid = verify(message, signature, publicKey)

// Compute PKH for on-chain registration
const pkh = computePKH(publicKey)

Safe Integration

import { prepareSafeTransaction } from '@luxfi/lamport'

const txData = prepareSafeTransaction(
  { to, value, data, operation },
  currentKeyPair,
  nextKeyPair,
  moduleAddress,
  chainId,
  safeTxHash
)

// Use txData.signature and txData.publicKey with LamportSafe contract

Threshold Signing

import {
  generateKeyShares,
  createSigningSession,
  signPartial,
  combineSignatures,
} from '@luxfi/lamport'

// Distributed key generation
const shares = generateKeyShares({
  threshold: 3,
  total: 5,
  signers: ['alice', 'bob', 'carol', 'dave', 'eve'],
})

// Create signing session
let session = createSigningSession(message, config)

// Each signer contributes their partial
const partial = signPartial(session, myShare)
session = addPartialSignature(session, partial)

// Combine when threshold reached
if (session.complete) {
  const signature = combineSignatures(session)
}

Solidity Contracts

Import contracts directly:

import "@luxfi/lamport/contracts/Lamport.sol";
import "@luxfi/lamport/contracts/LamportSafe.sol";
import "@luxfi/lamport/contracts/LamportThreshold.sol";
import "@luxfi/lamport/contracts/LamportOptimized.sol";

Contract ABIs

import {
  LamportVerifierAbi,
  LamportSafeAbi,
  LamportThresholdAbi,
  LamportOptimizedAbi,
} from '@luxfi/lamport'

Gas Costs

Method	Gas	Constant Time
Lamport.verifyMem	1,231,432	No
LamportOptimized.verify	163,848	No
verifyUnrolled	137,390	No
verifyConstantTime	145,051	Yes

Security

• Quantum-resistant: 128-bit security against Grover's algorithm
• One-time use: Each key can only sign ONE message
• Domain separation: Prevents cross-chain and cross-contract replay
• Constant-time: Optional side-channel resistant verification

⚠️ WARNING: Lamport keys are ONE-TIME USE. Never sign two different messages with the same key pair!

Architecture

┌─────────────────────────────────────────────────────────┐
│                    @luxfi/lamport                        │
├─────────────────────────────────────────────────────────┤
│  TypeScript SDK                                          │
│  ├── generateKeyPair() / generateKeyChain()             │
│  ├── sign() / signWithRotation()                        │
│  ├── verify() / computePKH()                            │
│  └── Threshold: generateKeyShares(), combineSignatures()│
├─────────────────────────────────────────────────────────┤
│  Solidity Contracts                                      │
│  ├── Lamport.sol        - Pure Solidity library         │
│  ├── LamportOptimized.sol - Assembly (164K gas)         │
│  ├── LamportSafe.sol    - Gnosis Safe module            │
│  └── LamportThreshold.sol - MPC key chain               │
└─────────────────────────────────────────────────────────┘

References

• Lamport (1979) - Original Lamport OTS paper
• NIST PQC - FIPS 203-205
• LP-4105 - Lux Proposal for Lamport signatures

License

BSD-3-Clause © Lux Network Team