Quantum isn’t here to replace classical computing; it’s a new instrument in the orchestra. Let’s tune our security to match.
What is quantum computing?
Quantum computing leverages quantum mechanical properties—superposition, entanglement, and interference—to perform certain calculations exponentially faster than classical computers. While today’s machines are noisy and small-scale, progress is steady.
“Quantum won’t replace classical computing; it will complement it for specific problem classes.”
Which crypto breaks—and which survives?
Shor’s algorithm threatens widely used public-key schemes like RSA and ECDSA. Symmetric crypto (e.g., AES) fares better; Grover’s algorithm provides a quadratic, not exponential, speedup—so doubling key sizes is a practical countermeasure.
Post-quantum algorithms
- CRYSTALS-Kyber (KEM) and CRYSTALS-Dilithium (signatures) are NIST’s frontrunners.
- Falcon offers compact signatures but is trickier to implement.
- SPHINCS+ is hash-based and stateless—larger signatures, great security margins.
Migration roadmap
- Inventory all crypto usage: TLS, data at rest, backups, code signing.
- Prioritize long-lived secrets. Protect data that must remain confidential for 10+ years.
- Adopt hybrid key exchange (classical + PQ) during the transition.
- Enable PQ in test environments; add metrics and fallbacks.
- Rotate certificates and keys with PQ-ready options when available.
Performance & benchmarks
PQ algorithms vary in size and speed. As a rule of thumb, Kyber key sizes are larger than ECDH, but handshake latency remains acceptable for most web apps.
FAQ
When should we start?
Now. Inventory and hybrid rollouts take time; you’ll be ready when vendors ship PQ-enabled updates.
Will quantum kill passwords?
No—passwords aren’t directly affected. But PQ strengthens key exchange and signatures; use passkeys and MFA for auth.