The transition that actually matters.
WHAT THE THREAT IS
A sufficiently large quantum computer breaking the public-key algorithms in use today.
WHAT IS AFFECTED
Key exchange in encrypted connections Digital signatures Certificates Anything relying on the difficulty of factoring or discrete logarithms
WHAT IS LESS AFFECTED
Symmetric encryption, which needs larger keys but remains sound Hash functions, similarly
WHAT HARVEST-NOW-DECRYPT-LATER MEANS
Capturing encrypted traffic today, to decrypt when capability exists.
WHY THAT MATTERS NOW
Data with a long secrecy requirement is already at risk.
WHAT POST-QUANTUM ALGORITHMS ARE
Classical algorithms believed resistant to quantum attack.
WHAT HAS HAPPENED
Standards bodies have selected algorithms, and adoption has begun.
WHAT HYBRID DEPLOYMENT MEANS
Using both a traditional and a post-quantum algorithm together.
WHY
If one is broken, the other still protects.
WHAT TO DO NOW
Inventory where public-key cryptography is used Establish what has a long secrecy requirement Prefer systems that can change algorithms without redesign Follow vendor support as it arrives
WHAT NOT TO DO
Adopt unproven algorithms independently.
