quantum-sign 0.1.0

Quantum-Sign: post-quantum signatures, format, policy, and CLI in one crate
Documentation

Quantum-Sign 🔐

The Digital Notary Stamp That Even Quantum Computers Can't Forge

Crates.io Documentation License MSRV Security Audit

Simple Answer: Quantum-Sign is a command-line tool that digitally signs software using quantum-resistant cryptography to prove the software is authentic and hasn't been tampered with.

Technical Details: A production-ready, pure-Rust implementation of post-quantum code signing with NIST-approved algorithms. Quantum-Sign provides quantum-resistant digital signatures using ML-DSA-87 (Module-Lattice Digital Signature Algorithm) with support for multi-party quorum signing, offline verification, and comprehensive policy enforcement.

🌟 Key Features

  • 🛡️ Quantum-Resistant: Built on FIPS 204 ML-DSA-87, secure against both classical and quantum computers
  • 🔒 Pure Rust: Zero unsafe code, memory-safe implementation with #![forbid(unsafe_code)]
  • 📦 Supply Chain Security: Strictly crates.io-only dependencies, no FFI or C libraries
  • ✅ Standards Compliant: Full compliance with NIST FIPS 204/205, SP 800-90A/B/C, SP 800-53
  • 👥 Quorum Signing: M-of-N threshold signatures for critical operations
  • 🔍 Offline Verification: Complete verification without network access
  • 📋 Policy Engine: Comprehensive policy enforcement with FIPS-only defaults
  • 🔐 Defense in Depth: Multiple security layers including domain separation, canonical encoding, and zeroization

📚 Table of Contents

🚀 Installation

As a CLI Tool

cargo install quantum-sign-cli

As a Library

Add to your Cargo.toml:

[dependencies]
quantum-sign = "0.1.0"
qs-crypto = "0.1.0"
qs-format = "0.1.0"
qs-policy = "0.1.0"

Build from Source

# Clone from crates.io source
cargo install quantum-sign-cli --git
# Or download source archive from crates.io
cargo build --release

⚡ Quick Start

Generate a Signing Key Pair

quantum-sign keygen \
  --profile mldsa-87 \
  --secret key.sk \
  --public key.pub

Sign a File

quantum-sign sign \
  --inp document.pdf \
  --sig document.qsig \
  --policy policy.json

Verify a Signature

quantum-sign verify \
  --inp document.pdf \
  --sig document.qsig \
  --trustdb ./trust

🏗️ Architecture

Quantum-Sign is structured as a workspace with specialized crates:

Crate Purpose Dependencies
qs-crypto Core cryptographic operations ml-dsa, sha2, sha3, zeroize
qs-drbg Deterministic random bit generator hmac, sha2, zeroize
qs-format .qsig CBOR format handling ciborium, serde
qs-policy Policy engine and validation serde, sha2
qs-cli Command-line interface All above crates
qs-verify Standalone verification qs-crypto, qs-format
qs-tsp RFC 3161 timestamping Future implementation
qs-transparency Transparency log support Future implementation

Cryptographic Flow

    File → SHA-512/256 Digest → Policy Binding → ML-DSA-87 Sign → CBOR Encode → .qsig File

📖 Usage Guide

Basic Signing

Create a policy file policy.json:

{
  "default_alg": "mldsa-87",
  "allow_algs": ["mldsa-87"],
  "require_fips_only": true,
  "require_level5": true,
  "digest_alg": "sha512",
  "offline_ok": true
}

Sign with policy enforcement:

# Generate keys
quantum-sign keygen --secret alice.sk --public alice.pub

# Import public key to trust store
quantum-sign trust import --public alice.pub --trustdb ./trust

# Sign artifact
quantum-sign sign \
  --inp artifact.bin \
  --sig artifact.qsig \
  --policy policy.json

Quorum Signing (M-of-N)

For critical operations requiring multiple approvals:

{
  "default_alg": "mldsa-87",
  "allow_algs": ["mldsa-87"],
  "required_signatures": {"m": 2, "n": 3},
  "digest_alg": "sha512"
}

# Initialize quorum signing
quantum-sign quorum init \
  --artifact critical.bin \
  --policy quorum-policy.json \
  --allowed-kid $KID1 --allowed-kid $KID2 --allowed-kid $KID3

# Each signer creates a fragment
quantum-sign quorum cosign \
  --intent critical.qsi \
  --secret alice.sk --public alice.pub \
  --fragment alice.csf \
  --append critical.qsig.part

quantum-sign quorum cosign \
  --intent critical.qsi \
  --secret bob.sk --public bob.pub \
  --fragment bob.csf \
  --append critical.qsig.part

# Seal into final signature (requires 2 valid signatures)
quantum-sign quorum seal \
  --part critical.qsig.part \
  --out critical.qsig \
  --trust-dir ./trust

Verification

Standard verification:

quantum-sign verify \
  --inp document.pdf \
  --sig document.qsig \
  --trustdb ./trust

JSON output for automation:

quantum-sign verify \
  --inp document.pdf \
  --sig document.qsig \
  --trustdb ./trust \
  --json

Output format:

{
  "status": "ok",
  "alg": "mldsa-87",
  "digest_alg": "sha512",
  "domain": "quantum-sign-v1",
  "canonical": true,
  "m": 2,
  "n": 3,
  "kids_verified": 2,
  "verified_kids": ["abc123...", "def456..."],
  "policy_hash_hex": "...",
  "file_digest_hex": "..."
}

Trust Management

Import and list trusted public keys:

# Import a public key (PEM or DER format)
quantum-sign trust import --public alice.pub --trustdb ./trust
# Output: imported abc123def456... -> ./trust/abc123def456.spki

# List all trusted keys
quantum-sign trust list --trustdb ./trust
# Output:
# abc123def456 ./trust/abc123def456.spki
# 789abcdef012 ./trust/789abcdef012.spki

🔒 Security

Threat Model

Quantum-Sign defends against:

  • Quantum computer attacks on signatures
  • Supply chain attacks via dependency control
  • Downgrade attacks via policy enforcement
  • Key compromise via quorum signing
  • Tampering via canonical encoding
  • Memory disclosure via zeroization

Security Features

  1. Cryptographic Security

    • ML-DSA-87 (NIST Level 5 security)
    • HMAC-DRBG with continuous health tests
    • Constant-time operations
    • Automatic key material zeroization

  2. Implementation Security

    • Pure Rust, zero unsafe code
    • Memory-safe by construction
    • No FFI or external dependencies
    • Strict input validation

  3. Operational Security

    • Offline-first verification
    • Policy-bound signatures
    • Audit logging support
    • Reproducible builds

Compliance

  • FIPS 204: ML-DSA specification
  • FIPS 205: SLH-DSA specification
  • SP 800-90A/B/C: DRBG requirements
  • SP 800-53 Rev.5: Security controls
  • SP 800-131A: Algorithm transitions

📚 Documentation

Core Documentation

  • Security Requirements - Comprehensive security analysis
  • QSig Format Specification - Detached signature format
  • API Documentation - Rust API reference

Examples

Example usage patterns:

Basic Signing

use qs_crypto::{keypair_mldsa87, sign_mldsa87, HmacSha512Drbg};
use qs_policy::Policy;

let mut drbg = HmacSha512Drbg::from_os(Some(b"app-context"))?;
let keypair = keypair_mldsa87(&mut drbg)?;
// Sign with policy binding...

Custom Policy

use qs_policy::{Policy, RequiredSignatures};

let policy = Policy {
    default_alg: "mldsa-87".into(),
    allow_algs: vec!["mldsa-87".into()],
    required_signatures: Some(RequiredSignatures { m: 2, n: 3 }),
    require_fips_only: true,
    require_level5: true,
    digest_alg: "sha512".into(),
    ..Default::default()
};

Performance

On Apple M1/M2:

  • Key generation: ~2ms
  • Signing (SHA-512): ~3ms
  • Verification: ~2ms
  • Quorum seal (3 signatures): ~7ms

🤝 Development

# Run tests
cargo test --workspace --all-features

# Format code
cargo fmt --all

# Lint
cargo clippy --all-targets --all-features -- -D warnings

# Security audit
cargo audit
cargo deny check

# Build documentation
cargo doc --no-deps --open

📜 License

Licensed under either of:

  • Apache License, Version 2.0 (LICENSE-APACHE)
  • MIT License (LICENSE-MIT)

at your option.

🙏 Acknowledgments

  • NIST PQC team for ML-DSA specification
  • Rust Crypto community for foundational libraries
  • Security researchers and contributors

⚠️ Security Warning

This is cryptographic software. While we've taken extensive precautions:

  • Always use the latest version
  • Review security advisories on crates.io
  • Test thoroughly in your environment
  • Consider professional security audit for critical uses

📞 Contact

For security issues, please email sic.tau@pm.me with subject line "[SECURITY] Quantum-Sign".

Building quantum-resistant security for the classical world 🔐