← Quantum Computing Fundamentals
Day 8 of 14
Quantum Cryptography & Post-Quantum Security
The Cryptopocalypse Timeline
HARVEST NOW DECRYPT LATER (HNDL): Nation-state adversaries (primarily China, Russia) are already collecting encrypted internet traffic with the explicit plan to decrypt it once quantum computers are powerful enough. Data encrypted today with RSA-2048 may be deciphered within 10-15 years.
WHAT'S AT RISK: Government secrets, corporate IP, personal financial data, medical records, anything encrypted with RSA or ECC today.
THE TIMELINE: Most cryptographers estimate a cryptographically relevant quantum computer (CRQC) could exist between 2030-2040. Government timelines are classified, but the urgency of current post-quantum standardisation suggests serious concern.
Post-Quantum Cryptography (PQC)
NIST finalised the first post-quantum standards in 2024:
ML-KEM (CRYSTALS-Kyber): Key encapsulation — replacing RSA/ECDH for key exchange. Based on the hardness of lattice problems, not integer factoring.
ML-DSA (CRYSTALS-Dilithium): Digital signatures — replacing RSA/ECDSA. Also lattice-based.
SLH-DSA (SPHINCS+): Hash-based signatures. More conservative, larger signatures.
QUANTUM KEY DISTRIBUTION (QKD): Using actual quantum physics to distribute cryptographic keys. Any eavesdropping collapses the quantum state and is detectable. Already deployed in some government and banking networks in China and Europe. Requires dedicated quantum channels (fibre or satellite).
YOUR ACTION: If you run any web services, plan your migration to hybrid PQC/classical schemes. Major browsers and TLS libraries are already implementing this.
⚡ Today's Action
Check if any of your services use certificate pinning or custom TLS implementations. These will need the earliest migration. Standard HTTPS using TLS 1.3 will be updated by browser vendors — custom crypto won't.
💡 Pro Tip
Post-quantum cryptography doesn't require a quantum computer — it runs on classical hardware. Start evaluating PQC for any long-lived sensitive systems now, not when quantum computers arrive.