Post-Quantum Readiness Starts With Your Keys: A Practical Framework for Enterprise Security

Map Your Cryptographic Inventory

Start by removing guesswork. Build a live inventory of what you protect, where keys live, and how they flow across systems. Unknowns are where the risk hides, especially as PQC introduces new key types and longer lifecycles.

Identify all keys and certificates

Document every key and certificate by system and purpose. Record how each key was generated, its entropy source, storage location, and access permissions. Track certificate authorities, issuance paths, and expiry dates and replace any software-generated-keys that should be recreated inside a Hardware Security Module (HSM).

Classify data by retention and re-use risk

Focus first on data that must remain confidential for years. Tag assets by confidentiality horizon: five, ten, fifteen years and prioritize long-life data for early PQC protection. Design data handling so that long-life material gains quantum-resistant protection first. Don’t forget backups, archives, and analytics platforms where data may be replicated.

Assess legacy systems and algorithm exposure

List where RSA and elliptic curve cryptography (ECC) are still in use, and identify dependencies. Note which services can handle larger keys or slower operations, and which may struggle with payload sizes, handshake limits, or message formats.

This assessment defines your migration priorities and helps avoid late surprises.

Choose Your Hybrid Strategy

Post-quantum transition is not a flip of a switch – it’s a phased journey. The safest path is hybrid, combining classical and quantum-resistant algorithms to maintain interoperability and reduce risk.

Why classical + PQC works

Run classical and quantum-resistant algorithms side by side. Dual-signature schemes, where both a classical and a post-quantum signature must be validated, allow you to test new mechanisms in production without disrupting what already works. This gives you time to adapt while maintaining security.

Performance, key size and system constraints

Expect larger keys and longer signatures. Some post-quantum schemes increase message sizes and verification times. Benchmark performance on the HSMs that generate and protect those keys. Check API payload limits, network MTUs, database field sizes, and log pipelines. Early testing prevents rollout friction later.

Prioritize systems by risk and value

Sequence transitions by impact, not convenience. Start with high-value, long-lived assets: identity roots, code-signing, document signing, critical data at rest, and high-sensitivity network links. Short-lived session traffic with low residual value can follow once foundations are set.

Embed PQC Into Your HSM and Key-Management Controls

Algorithms will evolve. Your root of trust should not. Anchor post-quantum adoption in HSM-backed key management so creation, storage, and sensitive operations stay inside tamper-resistant hardware with clear evidence of control.

The HSM as root of trust

Generate new keys inside the HSM. Keep private material non-exportable whenever possible. Use the HSM to enforce signing, decryption, and key wrapping policies. Treat it as the secure vault for your most sensitive cryptographic operations, not just a performance booster.

Lifecycle, entitlements and auditability

Define who can generate, use, rotate, export, or destroy keys. Apply least privilege, require multi-authorisation for high-risk operations, and record every action with non-repudiation. Rotation policies should reflect the realities of post-quantum algorithms with longer signatures size and key lifecycles. Maintain clear, immutable audit trails that can withstand regulatory or forensic scrutiny.

Account for cloud and AI-agent workflows

Cloud convenience doesn’t replace key ownership. If your data sits within one cloud, keep the keys somewhere you control – or even better, within your own HSM cluster. This maintains sovereignty and prevents a single provider from controlling your entire trust chain. 

As AI agents begin to trigger actions on your behalf, add attestation so you can show who requested what, which model acted, and when. Your post-quantum plan should include how these agent-initiated operations are authorised and logged.

Timeline, Governance and Risk Signalling

Post-quantum readiness isn’t a one-off project—it’s an ongoing program. Assign owners, phase the work, and establish clear metrics that demonstrate progress and control.

Build a phased transition roadmap

Work in four moves: discovery, pilot, limited rollout, and enterprise adoption, followed by verification. Discovery builds your inventory and exposure map. Pilots prove performance and process on one system with clear success criteria. Limited rollout expands to a small set of critical services. 

Assign roles and accountability

Appoint a single leader for cryptographic agility – someone empowered to set priorities, approve trade-offs, and halt risky moves.

Define roles across security, platform, and application teams. Engineering will need to adjust interfaces. Risk will need to update policies. Procurement will need refreshed vendor criteria. Short, regular updates stop drift when priorities collide.

Produce audit-ready signals today

Track essential metrics: coverage percentage, failed controls, open exceptions, and resolution speed. Keep a signed record of every key you create, use, rotate, and retire.

Prepare a short briefing pack for senior stakeholders that summarises current exposure, planned milestones, and risks that need decisions. When regulators or boards request evidence, you’ll have it ready.

Where to Begin: Quick-Start Checklist

You don’t need a multi-year plan to start. Take these actions this quarter:

• Inventory keys and certificates across your top ten critical systems, and record owners.

• Tag long-life data assets by confidentiality horizon and business impact.
• Benchmark HSM and API performance with short-listed quantum-resistant algorithms.
• Define where dual-signature will run first and how verifiers will check both paths.
• Update key-management policy with PQC roles, rotation rules, and evidence requirements.
• Schedule a pilot on one high-value, low-complexity system, then publish what you learned.

Final Thoughts: The Quantum Era Rewards Cryptographic Agility

True post-quantum resilience starts with your keys — not your code.

Understand what you protect, how long it must remain secure, and anchor every change in hardware-backed key management. Organisations that treat cryptography as a living adaptive system will lead with trust and confidence when quantum capabilities emerge.

To explore these principles further, listen to our CEO, Robert Rogenmoser unpacking real-world trade-offs on The Security Strategist podcast.