FedRAMP 20x: Build a Cryptographic Module Inventory by Service

A list of approved products does not tell an engineering team which cryptographic module a particular service actually uses. Build the inventory from the service outward: identify the cryptographic operation protecting federal customer data, trace its implementation, and attach the evidence behind the module and version identification.

This FedRAMP 20x cryptographic module inventory workflow is editorial guidance for Class B/C teams. The suggested fields below are a practical working record, not an official template or a determination that a particular deployment complies.

Separate documentation from module-selection rules

CMU-CSO-CMD requires providers to document modules used in each service, or groups of services using the same modules, where cryptographic services protect federal customer data. That documentation must include whether the modules have NIST Cryptographic Module Validation Program validation or are update streams of such modules. Official CMU rules

CMU-CSO-UVM uses different force for module selection: Class B providers MAY use modules or update streams with active CMVP validations, while Class C providers SHOULD use them when protecting federal customer data. Keep those class-specific statements separate from the mandatory documentation task. Treat this inventory as evidence for a review, not as a waiver of other applicable obligations.

CMU-CSO-CAT separately says providers SHOULD configure agency tenants to use cryptographic services with actively validated modules or their update streams by default when those modules are available. A product's supported options and a tenant's observed default configuration therefore deserve separate entries in your working record.

Trace each service to supporting evidence

Start with one service and ask its engineering owner to walk through where the cryptographic operation executes. Suggested fields include:

• Service or same-module service group, deployment context, and implementation owner.
• Cryptographic service protecting the relevant data, with a link to the implementation evidence.
• Module identity and version, plus the evidence used to establish each.
• Validation reference or update-stream basis, with the source and review date.
• Algorithms used and the available evidence about their inclusion in the module's validation history.
• Agency-tenant default configuration, observation date, and any differences requiring investigation.

Group services only when you have evidence that the grouping accurately represents their module use. Keep unknown module versions visible as unknowns. A dependency name from a build file may be a useful lead, but ask the owner to connect it to the deployed implementation before treating it as the answer.

Review update streams and tenant defaults explicitly

The CMU-CSO-UVM note states that newly added algorithms that were never previously validated fall outside the scope of update-stream usage under these rules. Do not treat a familiar module name as sufficient evidence for every algorithm introduced in a later version. Module-use statement and note

For example, if a service owner supplies a validation reference for an earlier module version, record the claimed update relationship and the evidence supporting it. If the version also introduces a new algorithm, give that question its own review item. Avoid silently extending the earlier validation to that algorithm.

Then compare documented tenant defaults with observed configuration. If they disagree, preserve both observations, assign an owner, and establish which deployment or tenant population the evidence covers. Do not mark a recommendation satisfied merely because an option exists in a configuration menu.

Keep review decisions and timing visible

The CMU dates for 20x list July 4, 2026 for optional adoption and obtaining initial certification, and January 1, 2027 for maintaining ongoing certification. The grace period ends at the first FedRAMP independent assessment started after January 1, 2027. These dates come from the current CMU rules, not a new deadline created by this inventory exercise.

Bring missing or conflicting evidence to the engineering and assessment owners. Keep the inventory tied to current implemented services and record unresolved questions alongside completed entries. Revisit the affected records when implementations or defaults change; choose an operating cadence suited to the actual change process rather than inventing a universal schedule.