Imported from mukul975/anthropic-cybersecurity-skills (skills/performing-post-quantum-cryptography-migration/SKILL.md). Install upstream with npx skills add mukul975/anthropic-cybersecurity-skills --skill performing-post-quantum-cryptography-migration. Copyright stays with the author (Apache-2.0).

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:

Standard	Algorithm	Renamed To	Purpose	Based On
FIPS 203	CRYSTALS-Kyber	ML-KEM	Key Encapsulation Mechanism	Module lattice
FIPS 204	CRYSTALS-Dilithium	ML-DSA	Digital Signatures	Module lattice
FIPS 205	SPHINCS+	SLH-DSA	Digital Signatures (backup)	Stateless hash

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:

Algorithm	Usage	Quantum Threat	Migration Priority
RSA-2048/4096	Key exchange, signatures, encryption	Shor's algorithm breaks factoring	Critical
ECDH (P-256, P-384)	TLS key exchange	Shor's algorithm breaks ECDLP	Critical
ECDSA	Code signing, TLS certificates	Shor's algorithm breaks ECDLP	Critical
DSA	Legacy signatures	Shor's algorithm breaks DLP	Critical
DH (Diffie-Hellman)	Key exchange	Shor's algorithm breaks DLP	Critical
AES-128	Symmetric encryption	Grover's halves key strength	Medium (upgrade to AES-256)
SHA-256	Hashing	Grover's reduces to 128-bit	Low (still adequate)

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)
Certificate signature algorithms (RSA, ECDSA)
Cipher suite configurations
Certificate key sizes and expiration dates

Phase 2: Crypto-Agility Assessment

Evaluate the organization's ability to swap cryptographic algorithms without major infrastructure changes:

# Assess crypto-agility readiness
python scripts/agent.py --action assess_agility \
    --scan-results tls_inventory.json \
    --output agility_report.json

Key assessment areas:

Protocol flexibility: Can TLS configurations be updated without downtime?
Library versions: Do deployed crypto libraries support PQC algorithms?
Certificate infrastructure: Can CA issue PQC certificates?
Key management: Can KMS handle larger PQC key sizes?
Hardware constraints: Can HSMs support PQC operations?

Phase 3: Hybrid TLS Readiness Testing

Test whether infrastructure supports hybrid key exchange with X25519MLKEM768:

# Test hybrid TLS support on target servers
python scripts/agent.py --action test_hybrid_tls \
    --target server.example.com:443 \
    --output hybrid_tls_report.json

OpenSSL 3.5+ (native ML-KEM support):

# Test with native PQC support
openssl s_client -connect server.example.com:443 \
    -groups X25519MLKEM768

OpenSSL 3.0-3.4 with oqs-provider:

# Configure oqs-provider
# /etc/ssl/openssl-oqs.cnf
[openssl_init]
providers = provider_sect

[provider_sect]
default = default_sect
oqsprovider = oqsprovider_sect

[default_sect]
activate = 1

[oqsprovider_sect]
activate = 1
module = /usr/lib/oqs-provider/oqsprovider.so

# Test hybrid TLS
OPENSSL_CONF=/etc/ssl/openssl-oqs.cnf \
openssl s_client -connect server.example.com:443 \
    -groups x25519_mlkem768

Web Server Configuration for Hybrid TLS:

Apache httpd:

SSLEngine on
SSLCertificateFile /etc/ssl/certs/server.crt
SSLCertificateKeyFile /etc/ssl/private/server.key
SSLOpenSSLConfCmd Curves X25519MLKEM768:X25519:prime256v1
SSLProtocol -all +TLSv1.2 +TLSv1.3

NGINX:

ssl_ecdh_curve X25519MLKEM768:X25519:prime256v1;
ssl_protocols TLSv1.2 TLSv1.3;
ssl_prefer_server_ciphers on;

Phase 4: ML-KEM Key Encapsulation Validation

Validate that ML-KEM (CRYSTALS-Kyber) key encapsulation works correctly in your environment:

# Test ML-KEM key encapsulation at all security levels
python scripts/agent.py --action test_mlkem \
    --output mlkem_validation.json

ML-KEM parameter comparison:

Parameter	ML-KEM-512	ML-KEM-768	ML-KEM-1024
Security Level	NIST Level 1	NIST Level 3	NIST Level 5
Public Key Size	800 bytes	1,184 bytes	1,568 bytes
Ciphertext Size	768 bytes	1,088 bytes	1,568 bytes
Shared Secret	32 bytes	32 bytes	32 bytes
Comparable To	AES-128	AES-192	AES-256

Phase 5: ML-DSA Digital Signature Validation

Validate ML-DSA (CRYSTALS-Dilithium) signature operations:

# Test ML-DSA digital signatures
python scripts/agent.py --action test_mldsa \
    --output mldsa_validation.json

ML-DSA parameter comparison:

Parameter	ML-DSA-44	ML-DSA-65	ML-DSA-87
Security Level	NIST Level 2	NIST Level 3	NIST Level 5
Public Key Size	1,312 bytes	1,952 bytes	2,592 bytes
Signature Size	2,420 bytes	3,293 bytes	4,595 bytes
Secret Key Size	2,560 bytes	4,032 bytes	4,896 bytes

Phase 6: Migration Roadmap Generation

Generate a prioritized migration roadmap based on inventory and assessment results:

# Generate complete migration roadmap
python scripts/agent.py --action roadmap \
    --scan-results tls_inventory.json \
    --agility-results agility_report.json \
    --output migration_roadmap.json

The roadmap prioritizes systems by:

Data sensitivity: Systems handling long-lived secrets migrate first
Exposure level: Internet-facing services before internal
Crypto-agility: Systems that can easily swap algorithms first
Compliance requirements: Federal/regulated systems per NIST IR 8547 timeline
Dependency chains: Libraries and frameworks before applications

Examples

Full Assessment Pipeline

# Step 1: Scan all TLS endpoints
python scripts/agent.py --action scan_tls --targets hosts.txt --output scan.json

# Step 2: Assess crypto-agility
python scripts/agent.py --action assess_agility --scan-results scan.json --output agility.json

# Step 3: Test hybrid TLS on critical servers
python scripts/agent.py --action test_hybrid_tls --target critical.example.com:443

# Step 4: Validate ML-KEM support
python scripts/agent.py --action test_mlkem --output mlkem.json

# Step 5: Validate ML-DSA support
python scripts/agent.py --action test_mldsa --output mldsa.json

# Step 6: Generate migration roadmap
python scripts/agent.py --action roadmap --scan-results scan.json --agility-results agility.json --output roadmap.json

Quick Server Assessment

# Single server PQC readiness check
python scripts/agent.py --action scan_tls --target server.example.com:443

Validation Checklist

References

NIST PQC Standards: https://csrc.nist.gov/projects/post-quantum-cryptography
FIPS 203 (ML-KEM): https://csrc.nist.gov/pubs/fips/203/final
FIPS 204 (ML-DSA): https://csrc.nist.gov/pubs/fips/204/final
FIPS 205 (SLH-DSA): https://csrc.nist.gov/pubs/fips/205/final
NIST SP 1800-38 Migration Guide: https://www.nccoe.nist.gov/crypto-agility-considerations-migrating-post-quantum-cryptographic-algorithms
NIST IR 8547 Transition Timeline: https://csrc.nist.gov/pubs/ir/8547/ipd
Open Quantum Safe Project: https://openquantumsafe.org/
oqs-provider for OpenSSL: https://github.com/open-quantum-safe/oqs-provider
OQS TLS Integration: https://openquantumsafe.org/applications/tls.html
CISA PQC Migration Strategy: https://www.cisa.gov/sites/default/files/2024-09/Strategy-for-Migrating-to-Automated-PQC-Discovery-and-Inventory-Tools.pdf
IETF Hybrid Key Exchange Draft: https://datatracker.ietf.org/doc/draft-ietf-tls-hybrid-design/
CycloneDX Crypto BOM: https://cyclonedx.org/use-cases/cryptographic-key/

performing-post-quantum-cryptography-migration

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