Educational guidance by GC Solutions LLC. Not a formal assessment, certification or production change authorization.
Inventory what the service actually uses
A product may advertise an algorithm without enabling it in the deployed configuration or using it in the application path that matters. Record algorithm purpose, platform and software versions, configuration evidence, application dependencies, owners and evidence age. Keep advertised, supported, enabled and observed-used capability separate.
Identify public-key dependencies in certificates, key establishment, signatures, software trust, payment services and externally managed integrations. Where direct evidence is unavailable, label the assertion and the confidence limitation rather than filling the gap with an assumption.
Match the standard to its purpose
NIST approved three principal post-quantum standards in 2024. FIPS 203 specifies ML-KEM for key establishment. FIPS 204 specifies ML-DSA digital signatures, and FIPS 205 specifies SLH-DSA digital signatures. These purposes are not interchangeable.
An algorithm standard does not prove that a particular HSM module, firmware build, library or end-to-end service is validated or operationally compatible. Confirm exact-version vendor documentation and test the intended integration before adopting a target state.
Prioritize business consequence and feasibility
A migration roadmap needs more than a list of algorithms. Consider how long information must remain protected, which systems anchor trust, service criticality, dependency concentration, change windows, vendor readiness and rollback constraints. Document which factors are known and which still need evidence.
Separate exposure, migration priority, difficulty and evidence confidence. An uncertain inventory does not imply low risk; a difficult migration does not automatically make it the first change to execute. Executive decisions should have a stated rationale and an accountable owner.
Plan a controlled change
Define prerequisites, compatibility tests, acceptance criteria, operating procedures and a rollback approach before scheduling production work. Treat crypto-agility as the capacity to make a governed change across services, not simply as purchasing a new cryptographic feature.
Regulatory applicability depends on the organization, jurisdiction, contract and control framework. Do not infer a universal commercial banking deadline from a federal standard or treat a readiness assessment as legal advice or certification.