Post-Quantum Cryptography — Prepare for the Quantum Threat

A quantum computer that can break RSA doesn’t exist yet. But attackers are already collecting data — harvest now, decrypt later.

The Threat¶

Shor’s algorithm breaks RSA, ECDSA, DH. Grover’s weakens symmetric cryptography by half.

NIST Standards¶

• CRYSTALS-Kyber (ML-KEM): Key encapsulation — replacing RSA/ECDH
• CRYSTALS-Dilithium (ML-DSA): Digital signatures
• SPHINCS+ (SLH-DSA): Hash-based signatures — fallback

What to Do Now¶

• Cryptography inventory — where do you use RSA/ECDSA?
• Crypto agility — the ability to swap algorithms
• Hybrid mode — classical + post-quantum simultaneously
• Data classification — what must remain secret for 20 years?

No Time to Panic, Time to Plan¶

Cryptography migration takes years. Start with an inventory and crypto agility.