FIPS 140-3 Module boundaries FAQ

FIPS 140-3 applies to cryptographic modules and covers security requirement areas such as module specification, module interfaces, roles and services, software and firmware security, operating environment, physical security, sensitive security parameter management, self-tests, and lifecycle assurance.

For a boundary question, start with the module embodiment: hardware, software, firmware, or hybrid. Then identify which executable code, firmware, circuitry, interfaces, services, and operational environment assumptions are inside the cryptographic module and which supporting platform or application elements are outside it.

CMVP implementation guidance treats binding and embedding from the perspective of the module under validation, called the Implementation Under Test. An embedded existing validated module is wholly contained within the IUT module boundary and provides services solely to the IUT.

A bound module is different: the IUT has a separate, disjoint cryptographic boundary and depends on an existing validated module. In binding cases, application services can be available from either cryptographic module, so the documentation needs to distinguish what each module provides.

Boundary documentation should be specific enough for a customer, assessor, or procurement reviewer to understand the module being claimed without confusing product packaging with the validated cryptographic module.

The safest public-facing wording is narrow: name the module, certificate context if one exists, module type, tested operational environment where relevant, interfaces, services, and any bound or embedded existing validated module. Avoid implying that an entire product, cloud service, platform, or dependency is FIPS 140-3 validated when only a defined module is in scope.