Why Quantum Breaks Everything
A sufficiently powerful quantum computer running Shor's algorithm can factorise large integers and compute discrete logarithms in polynomial time — directly breaking RSA, Diffie-Hellman, and Elliptic Curve Cryptography that secures virtually all of today's internet communications.
Grover's algorithm provides a quadratic speedup for brute-force searches, effectively halving the security of symmetric algorithms — AES-128 becomes equivalent to ~64-bit classical security. AES-256 remains viable by doubling key lengths.
"Harvest Now, Decrypt Later" — The Immediate Threat
Nation-state adversaries are already collecting encrypted traffic today, storing it for decryption once quantum computers are available. This means data encrypted with RSA/ECC right now may be compromised in 5–15 years. Long-lived secrets — medical records, financial data, state secrets — need quantum-safe protection today.
NIST PQC Standards (FIPS 203–205)
After an 8-year global competition, NIST finalised the first post-quantum cryptographic standards in August 2024 — FIPS 203, 204, and 205. These form the foundation of quantum-safe cryptography for the next decades.
Based on Module Learning With Errors (MLWE) — a lattice problem believed to be hard for both classical and quantum computers. Replaces RSA/ECDH for key exchange. Produces shared keys for symmetric encryption.
Based on Module Learning With Errors (MLWE) and Short Integer Solution (SIS) lattice problems. Replaces RSA and ECDSA for digital signatures. Used for code signing, certificate authorities, and document authentication.
Based on hash function security — conservative and well-understood assumption. Slower than Dilithium but provides a security diversity backup not based on lattice problems. Important for long-term trust anchors.
Based on NTRU lattice problems. Produces significantly smaller signatures than Dilithium — critical for constrained environments. Finalisation expected 2025 as FIPS 206.
Lattice-Based Cryptography
Lattice cryptography derives its security from the hardness of lattice problems — specifically the Learning With Errors (LWE) and Short Integer Solution (SIS) problems. These are believed to be computationally hard even for quantum computers.
Why Lattice Problems Are Quantum-Safe
Shor's algorithm exploits the periodic structure of RSA/ECC mathematical groups. Lattice problems have no such exploitable structure. The best known quantum algorithms for LWE offer only negligible speedup over classical algorithms, making them quantum-resistant at practical security levels.
CRYSTALS-Kyber KEM Mechanism
Kyber is the primary NIST-standardised Key Encapsulation Mechanism (KEM) for post-quantum key exchange. Understanding its flow is critical for enterprise migration planning.
Quantum-Safe Migration Roadmap
Migrating enterprise systems to post-quantum cryptography is a multi-year programme. The priority is crypto-agility — building systems that can swap algorithms without architecture changes.
Cryptographic asset discovery: identify all RSA/ECC usage across systems, certificates, protocols, libraries, HSMs, and API integrations. Create a cryptographic bill of materials (CBOM).
Risk-classify assets by sensitivity and lifespan. Long-lived secrets (PKI roots, signing keys) are highest priority. Assess vendor PQC roadmaps and library support.
Deploy hybrid classical+PQC schemes: X25519+Kyber for TLS, ECDSA+Dilithium for signatures. Hybrid provides classical security while gaining quantum resistance. No "cliff edge" migration.
Replace classical algorithms progressively. Start with highest-risk, longest-lived data. Update PKI infrastructure, code-signing pipelines, secure messaging, and API authentication.
Monitor NIST guidance evolution. Track new PQC breaks. Maintain crypto-agility for algorithm rotation. Annual quantum threat reassessment.
Current Research Focus Areas
Research Disclaimer
This research is an independent academic and professional development activity. All analysis is based on publicly available NIST publications, IETF drafts, and academic literature. No proprietary or classified information is involved. The views expressed are personal and do not represent the position of any employer or organisation.