Lux Quantum-Safe Wallets and Multisig Standard

See also: LP-4: Quantum-Resistant Cryptography Integration in Lux

Abstract

Activation

Parameter	Value
Flag string	lp5-quantum-safe-wallets
Default in code	N/A
Deployment branch	N/A
Roll-out criteria	N/A
Back-off plan	N/A

LP-5 focuses on the design of Lux’s quantum-safe wallet infrastructure, including a new multisignature (multisig) standard that remains secure against quantum adversaries. As Lux transitions its core signatures to post-quantum algorithms (per LP-4), user-facing wallet technology must follow suit. This proposal introduces support for hash-based and lattice-based signature schemes in Lux wallets. It specifies that a user’s Lux address can be associated with a quantum-resistant public key, such as an XMSS or Dilithium public key, instead of or in addition to the traditional elliptic curve key. A major component is the Lux Safe, a quantum-safe multisig wallet service, which LP-5 formalizes at the protocol level. In a Lux Safe multisig account, multiple parties each hold a share of a post-quantum key or have independent PQ keys, and the account requires a threshold of signatures on any transaction. The use of threshold signing is carefully designed to be compatible with PQ algorithms. For instance, if using lattice-based signatures, the proposal outlines how to aggregate partial signatures or how to perform a secure distributed key generation such that no single device ever holds the full private key (applying MPC techniques akin to those used in threshold ECDSA, but now in a lattice context). Recognizing the novelty of threshold PQ signatures, LP-5 references ongoing research in this arena – for example, experiments combining Falcon (lattice signature) with threshold schemes, and stateful hash-based multisigs where each cosigner uses a distinct XMSS tree for each approval. The Lux Safe design takes inspiration from conventional multisigs (like Bitcoin’s M-of-N script and Ethereum’s smart contract wallets) but builds in quantum resilience. It also emphasizes usability and security: for instance, using a hierarchical derivation of many one-time hash-based keys under the hood so that the wallet can generate a new PQ one-time address for each transaction (mitigating reuse i... The proposal cites the IETF’s XMSS standard (RFC 8391) as evidence that hash-based signatures are mature enough for production use. It also references that Lux Safe is already implemented as a product in the ecosystem, highlighting it as “our quantum-safe multisig wallet”, to be integrated at protocol level. Through LP-5, Lux aims to provide users and institutions with high assurance that even if large-scale quantum computers emerge, funds secured in Lux multisig wallets (which might protect exchange reserves or DAO treasuries) will remain safe. This enhances Lux’s appeal for “quantum-resistant custody.” In summary, LP-5 extends Lux’s security to the user and application layer by defining standards for quantum-resistant key management and multisignature transactions, aligning with global efforts (by NIST and IETF) to make cryptocurrency systems ready for the quantum age.

Motivation

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Specification

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Rationale

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Backwards Compatibility

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Security Considerations

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Implementation

Lux Safe Multisig Wallet

Location: ~/work/lux/safe/ GitHub: github.com/luxfi/safe/tree/main

Quantum-Safe Wallet Components:

• app/ - Next.js wallet application (React, TypeScript)
• react/ - Reusable React components for Safe interface
• contracts/ - Smart contract module (Solidity)

Key Features:

• M-of-N multisig with post-quantum key support
• Hierarchical deterministic (HD) wallet derivation
• One-time signature capability (XMSS/hash-based)
• Zero-knowledge proof integration for privacy

Testing & Documentation:

cd ~/work/lux/safe/app
npm install && npm test

Wallet CLI and Key Management

Location: ~/work/lux/cli/cmd/ GitHub: github.com/luxfi/cli/tree/main/cmd

Quantum-Safe Features:

• Post-quantum key generation (ML-DSA, SLH-DSA, ML-KEM support)
• Hybrid key management (classical + post-quantum)
• Secure key storage and recovery
• Transaction signing with quantum-resistant algorithms

Testing:

cd ~/work/lux/cli
make test  # Run full CLI test suite

Test Cases

Unit Tests

1. Cryptographic Primitives

   • Test key generation
   • Verify signature creation
   • Test signature verification

2. Post-Quantum Security

   • Verify NIST compliance
   • Test parameter validation
   • Validate security levels

3. Performance Benchmarks

   • Measure key generation time
   • Benchmark signing operations
   • Test verification throughput

Integration Tests

1. Hybrid Signature Schemes

   • Test classical-PQ combinations
   • Verify fallback mechanisms
   • Test key rotation

2. Network Integration

   • Test consensus with PQ signatures
   • Verify cross-chain compatibility
   • Test upgrade transitions

Copyright

Copyright and related rights waived via CC0.