Post-Quantum Certificates
The article explores the transition to post-quantum cryptography, explaining how quantum computers threaten current public-key algorithms and detailing the practical challenges of deploying new quantum-resistant certificate standards like ML-KEM and ML-DSA.
Background
- Today's TLS certificates (used to secure HTTPS) rely on algorithms like RSA that a large enough quantum computer could break. "Store now, decrypt later" makes this urgent — encrypted traffic captured today could be decrypted retroactively.
- Post-Quantum Cryptography (PQC) means new algorithms designed to resist quantum attacks. In 2024, NIST finalized the first standards: ML-KEM (key exchange) and ML-DSA (signatures).
- The article explores practical deployment hurdles: PQC certificates are 4-7 KB vs ~1 KB today, contain multiple keys, and may not fit in a single TLS round-trip. Load balancers, CAs, and browsers all need changes.
- Hybrid certificates (bundling a classical + post-quantum signature) are the near-term approach — they protect against weaknesses in new algorithms but inflate size further.