Performing Post-Quantum Cryptography Migration

When to Use

• When assessing organizational readiness for the NIST post-quantum cryptography transition
• When building a cryptographic inventory to identify quantum-vulnerable algorithms across infrastructure
• When evaluating hybrid TLS 1.3 configurations using X25519MLKEM768 key exchange
• When testing CRYSTALS-Kyber (ML-KEM) and CRYSTALS-Dilithium (ML-DSA) algorithm support
• When implementing crypto-agility to support both classical and post-quantum algorithms
• When preparing migration roadmaps aligned with NIST IR 8547 deprecation timelines
• When configuring oqs-provider with OpenSSL 3.x for post-quantum algorithm support

Prerequisites

• Python 3.8+ with cryptography, requests, pyOpenSSL libraries
• OpenSSL 3.0+ (3.5+ recommended for native ML-KEM/ML-DSA support)
• oqs-provider for OpenSSL (for hybrid TLS testing with older OpenSSL)
• Network access to target servers for TLS assessment
• Administrative access for infrastructure scanning
• Familiarity with PKI, TLS, and cryptographic protocols

Core Concepts

NIST Post-Quantum Cryptography Standards

NIST published three finalized PQC standards on August 13, 2024:

ML-KEM (FIPS 203) -- Primary standard for key exchange and encryption. Replaces RSA and ECDH for key establishment. Three security levels: ML-KEM-512, ML-KEM-768, ML-KEM-1024.

ML-DSA (FIPS 204) -- Primary standard for digital signatures. Replaces RSA and ECDSA for signing. Three security levels: ML-DSA-44, ML-DSA-65, ML-DSA-87.

SLH-DSA (FIPS 205) -- Backup signature standard using hash-based approach. Intended as fallback if lattice-based ML-DSA is found vulnerable. Larger signatures but conservative security assumptions.

Quantum-Vulnerable Algorithms

These classical algorithms are vulnerable to quantum attack via Shor's algorithm:

NIST Migration Timeline (IR 8547)

• 2024: Standards published, migration planning should begin
• 2030: Deprecation of quantum-vulnerable algorithms for most federal systems
• 2035: Complete removal of quantum-vulnerable algorithms from NIST standards
• Now: "Harvest now, decrypt later" attacks make early migration essential for long-lived secrets and data requiring long-term confidentiality

Hybrid TLS Key Exchange

During the transition period, hybrid key exchange combines a classical algorithm with a post-quantum algorithm. If either algorithm is secure, the connection remains protected.

Hybrid Key Exchange: X25519MLKEM768
  = X25519 (classical ECDH) + ML-KEM-768 (post-quantum)

Client Hello:
  supported_groups: X25519MLKEM768, X25519, secp256r1
  key_share: X25519MLKEM768

Server Hello:
  selected_group: X25519MLKEM768
  key_share: X25519MLKEM768

Shared Secret = KDF(X25519_shared || MLKEM768_shared)

Instructions

Phase 1: Cryptographic Inventory Scanning

The first step in PQC migration is discovering all cryptographic algorithm usage across the enterprise. This includes TLS configurations, certificates, code libraries, key stores, and protocol configurations.

# Scan TLS endpoints for quantum-vulnerable algorithms
python scripts/agent.py --action scan_tls \
    --targets targets.txt \
    --output tls_inventory.json

The scanner identifies:

• TLS protocol versions in use
• Key exchange algorithms (RSA, ECDH, DH -- all quantum-vulnerable)

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