FIPS 140-3 How should teams handle approved mode under FIPS 140-3

Start with the validated cryptographic module and the service the operator invokes. FIPS 140-3 specifies requirements for cryptographic modules, and IG 2.4.C distinguishes an approved security service from other services that may run while the module is in an approved mode. Show-status, version, and other non-security services do not become approved security services merely because they are available in that mode.

For a customer, procurement, or audit answer, identify the specific module certificate and version, the service being called, the approved algorithm or process used by that service, and the operator-visible indicator that shows the service is approved. A broad statement that a product is "in FIPS mode" is not enough when the module can expose approved and non-approved services or use context-sensitive algorithms.

The evidence must let a reader trace the answer from a module certificate and Security Policy to the exact service behavior. IG 2.4.C requires the Security Policy to list approved and non-approved services with their details and applicable indicators. The module must provide an externally accessible, operator-verifiable indicator; Security Policy text can explain that indicator but cannot replace it.

Evidence should also show the treatment of non-approved algorithms. IG 2.4.A permits limited uses in approved mode only when the algorithm does not meet a FIPS 140-3 requirement, does not compromise or improperly share an approved algorithm's CSP, and cannot be confused with a security function. A non-approved security function that claims security is not made approved by a mode setting or disclaimer.

Most approved-mode mistakes come from treating the mode as a switch that validates every cryptographic operation. FIPS 140-3 and the CMVP guidance require a more precise answer: which module, which service, which approved security function, which indicator, and which Security Policy rule.