The UK National Cyber Security Centre has given large organizations, critical national infrastructure operators, government, and companies with bespoke IT a clear post-quantum migration sequence. Its PQC migration timeline calls for full discovery, migration goals, and an initial plan by 2028; the highest-priority migrations and a refined roadmap by 2031; and migration of systems, services, and products by 2035.
These are NCSC target dates and guidance, not a claim that every UK organization is subject to an identical statutory deadline. But for organizations in regulated or critical sectors, the timeline is a strong basis for investment, supplier conversations, and governance expectations.
Why 2028 is closer than it looks
NCSC estimates that large organizations may need two to three years for discovery, assessment, strategy, and initial planning. The 2028 milestone is therefore not permission to wait. It is a completion target for foundational work that must begin now.
A full discovery exercise must cover more than internet-facing TLS. Public-key cryptography can appear in private PKI, identity and access systems, VPNs, code and firmware signing, document signatures, APIs, databases, backups, messaging, cloud services, hardware roots of trust, operational technology, and vendor-managed platforms.
Define what “full discovery” means
No single sensor sees every cryptographic dependency. A credible discovery program combines sources and records its coverage:
- Passive observations of cryptographic use in network traffic.
- Selected-asset active assessment for known coverage gaps.
- Configuration and appliance interrogation.
- Cloud-provider and certificate APIs.
- Software and cryptographic bills of materials.
- Architecture records, procurement data, and supplier evidence.
These signals must be reconciled. Duplicate assets, stale certificates, conflicting ownership records, and ambiguous product claims are normal. A canonical inventory should preserve provenance rather than hiding disagreement.
The initial plan needs dependencies and money
NCSC says the 2028 plan should identify the earliest high-priority work, supplier and physical-infrastructure dependencies, investment needs, and long-lived hardware roots of trust. This is materially different from a list of algorithms. It is a funded sequence of changes with accountable owners.
Prioritization should consider how long data must remain confidential, the impact of forged identities or signatures, mission and safety consequences, external exposure, upgrade availability, interoperability, and replacement lead time. Long-lived hardware and operational technology may need decisions years before software-only services.
Use the 2031 milestone to prove the operating model
By 2031, organizations should have completed early high-priority migrations and refined the route to 2035. The first migrations should therefore test more than technology. They should prove that the organization can discover cryptography, approve a target design, coordinate suppliers, manage fallback, validate the result, and retain evidence.
Useful progress measures include discovery coverage, high-risk dependencies with owners, supplier responses received, funded work, systems with PQC support enabled, vulnerable modes disabled, and completed changes backed by evidence. Counting products labelled “PQC-ready” is not sufficient.
Make discovery continuous
A 2028 inventory will not remain accurate until 2035 without continuous maintenance. Vista Platform is a self-hosted cryptographic system of record that connects discovery, canonical inventory, evaluation, action, and proof. It can help govern the program, but it does not generate PQC keys or perform every migration.
Read more about why PQC migration starts with inventory, review the Vista post-quantum approach, or try Vista Platform Core.