What is post-quantum cryptography?

Post-quantum cryptography is cryptography designed to resist attacks from both classical computers and future cryptographically relevant quantum computers.

What should security teams do first for quantum readiness?

Start with a cryptographic inventory and classify data by how long it must remain confidential. Systems with long-lived confidentiality or root-of-trust impact should be prioritized.

Why does harvest now decrypt later matter?

Adversaries may store encrypted data today and attempt to decrypt it later when quantum capability improves. Long-lived sensitive data is therefore exposed before large-scale quantum systems arrive.

Post-Quantum Cryptography Checklist for Security Teams

Checklist

Ten practical post-quantum steps.

Step 1

Build a cryptographic inventory

Find RSA, Diffie-Hellman, elliptic-curve cryptography, certificates, SSH keys, VPNs, TLS libraries, firmware signing, package signing, and encrypted archives.

Step 2

Classify data by confidentiality lifetime

Prioritize data that must remain confidential for years: medical records, legal archives, product designs, identity roots, government data, and sensitive customer records.

Step 3

Identify harvest-now-decrypt-later exposure

Assume adversaries may store encrypted traffic or archives today and attempt decryption when stronger quantum capability arrives.

Step 4

Ask vendors for PQC roadmaps

Require cloud, identity, VPN, HSM, certificate, device, SaaS, and security-tool vendors to explain post-quantum support timelines and customer actions.

Step 5

Test hybrid key exchange where available

Pilot post-quantum or hybrid cryptographic modes in non-production paths before attempting broad migration.

Step 6

Prioritize roots of trust

Start with systems that sign code, firmware, packages, certificates, device identity, and long-lived authentication material.

Step 7

Plan certificate and protocol migration

Map where TLS, SSH, S/MIME, VPN, PKI, mTLS, and service certificates depend on vulnerable algorithms or brittle tooling.

Step 8

Update procurement language

Add post-quantum readiness, crypto agility, exportable evidence, algorithm inventory, and migration support to vendor questionnaires.

Step 9

Track operational risk

Watch performance, key sizes, interoperability, hardware limits, logging gaps, rollback paths, and incident-response playbooks.

Step 10

Review annually

Post-quantum readiness should become a recurring architecture and risk review, not a one-time research memo.

Post-quantum cryptography checklist for security teams.