Build your cryptographic inventory
A complete cryptographic inventory identifies every system, application, protocol, and data store that uses cryptography. This is consistently the phase that surprises organisations most — in scope and in time required. Even with commercial discovery tooling, the inventory takes months for a mid-sized organisation, longer for large or complex ones.
NIST SP 1800-38 — the Migration to Post-Quantum Cryptography project — includes practical guidance on discovery tooling and inventory methodology. Commercial vendors including IBM, Entrust, and Keyfactor offer discovery tools that automate portions of the inventory for network-visible assets. OT and IoT assets remain the hardest to reach.
Prioritise by data longevity and breach impact
Once you have an inventory, you'll have more transition work than can be done simultaneously. The prioritisation framework has two dimensions: how long the data needs to remain confidential, and what the impact is if it's compromised.
Data confidentiality beyond 10 years, or catastrophic breach impact
The harvest-now-decrypt-later threat applies most acutely here. Certificate authority infrastructure, health records, legal and contractual data, strategic IP, government reporting systems, critical infrastructure OT.
Moderately sensitive data with medium-term confidentiality needs
Transition timeline can follow Tier 1 completion, but planning should begin now, in parallel. Internal communications, HR systems, financial reporting, customer data subject to retention requirements.
Transient or low-sensitivity data, short natural refresh cycles
Incorporate post-quantum requirements into planned upgrades rather than separate transition projects. Web applications, short-lived session tokens, systems already scheduled for replacement.
Assess your vendors
Most enterprise cryptography is vendor-implemented. Vendor assessment should be built into procurement immediately, and existing relationships reviewed. Vendors without credible post-quantum roadmaps for Tier 1 systems are a supply chain risk — document responses and act on gaps.
A credible answer names specific algorithms (ML-KEM, ML-DSA, SLH-DSA), specific release timelines, and alignment with NIST FIPS 203/204/205. "We're monitoring developments" isn't acceptable for Tier 1 systems.
Every product managing certificates, signing code, establishing encrypted connections, or handling authentication is in scope. Vendors who can't enumerate this are themselves a risk.
The ability to change algorithms without replacing the entire product. Vendors building this in now are better positioned — make it a procurement requirement for new systems from here on.
A contractual requirement for vendors selling to US federal or Five Eyes government customers. Their timeline is a concrete signal of seriousness — a useful benchmark even outside government procurement.
Begin migration on Tier 1 systems
With inventory complete and vendors assessed, Tier 1 migration can begin. The recommended approach is hybrid cryptography — post-quantum algorithms running alongside classical ones during the transition, giving immediate harvest-now-decrypt-later protection without requiring simultaneous decommissioning of classical infrastructure.
Govern and monitor, ongoing
Ongoing governance is required for structural reasons, not as compliance theatre — the threat landscape genuinely continues to evolve.
Algorithm evolution
NIST continues evaluating additional post-quantum algorithms. Future guidance may deprecate current standards. Build a process to monitor and respond.
Cryptanalytic developments
Post-quantum algorithms could be weakened by future research. Cryptography's history includes algorithms once considered sound. Monitoring academic research is essential.
Ongoing inventory
New systems deploy continuously. Procurement must incorporate post-quantum requirements so new systems don't reintroduce vulnerable cryptography.
How to present post-quantum risk to a board or risk committee
The transition requires sustained investment and executive sponsorship. Three anchors make the case effectively.
Frame it as present risk, not future
Harvest-now-decrypt-later means the risk is active today. The board doesn't need to believe a CRQC exists in 2027 to understand data encrypted now may be readable in 2035.
Anchor to regulatory obligations
ASD's ISM sets a 2030 target. APRA's CPS 234 requires managing emerging technology risks. For listed companies, ASIC disclosure obligations are relevant.
Use the peer comparison
Major banks, government agencies, and critical infrastructure operators already have active programmes. The question isn't whether — it's whether to lead or lag.
The minimum viable starting point — five actions, all available now
For organisations that haven't started, these actions have the highest impact per unit of effort and require no capital expenditure to begin.
Even an incomplete inventory is better than none. It surfaces the highest-priority systems quickly — start with network-visible assets using available tooling.
Name a single individual accountable for post-quantum transition progress. Without a named owner, the programme won't move at the required pace.
Add post-quantum roadmap requirements to vendor templates immediately. Every new system acquired should have a credible plan as a condition.
Frame the risk, the obligations, and the programme of work using the three anchors above. Sustained investment requires sponsorship earned early.
The largest attack surface and the most accessible starting point. Assess certificate inventory, key types, and CA configuration against post-quantum readiness.
What to take into your next risk conversation
Start the cryptographic inventory now
It takes longer than expected and surprises organisations on scope. An incomplete inventory started today beats a complete one started in 2027.
Prioritise by data longevity and breach impact
Tier 1 systems — long-term confidentiality or catastrophic breach — transition first. That risk exists today, regardless of when a CRQC arrives.
Vendor assessment is risk management, not paperwork
Vendors without credible roadmaps for Tier 1 systems are a supply chain risk. Make cryptographic agility a procurement requirement from now.
The board presentation frames a present risk
Harvest-now-decrypt-later, ASD obligations, and peer comparison are the three anchors. Sustained investment needs sponsorship earned through effective framing.
You've read the full Post-Quantum Cryptography series.
The roadmap is technical. The decisions that drive it are human.
Board briefings, vendor assessments, internal prioritisation debates, and the culture that determines whether your organisation acts before 2030 or scrambles after it — all people problems. Click or Flick Corporate builds the awareness foundation that makes those decisions informed, timely, and grounded in evidence.