FAQ item index

Search every question across sub-FAQs

Find the exact question, open the source answer card, and copy a direct link to the anchored sub-FAQ response.

Indexed coverage
25of25items
Across 8 modules • Updated May 9, 2026
Author
Sorena AI
Published
May 9, 2026
Updated
May 9, 2026
FIPS 140-3 Vendor Affirmation

What does vendor affirmation require for HSS?

For SP 800-208 HSS, IG C.O lists concrete conditions rather than a self-attestation shortcut. If HSS key generation or signature generation is implemented, the underlying LMS key generation and LMS signature generation operations need CAVP certificates. If HSS signature verification is implemented, the underlying LMS signature verification operation needs a CAVP certificate.

The same IG requires every LMS parameter set used inside the HSS tree to have the applicable CAVP certificates. It also requires CSTL source-code review of each supported HSS operation against RFC 8554 key generation, signature generation, and signature verification sections, with the results documented in TE02.20.04 of the Test Report.

  • Record the HSS operations implemented by the module: key generation, signature generation, signature verification, or a subset.
  • Map each implemented HSS operation to the required LMS CAVP certificates and parameter sets.
  • Verify that HSS appears in the Security Policy's Vendor-Affirmed Algorithms table and that LMS appears in the Approved Algorithms table with the associated certificate references.
Citations
CMVP Implementation Guidance for FIPS 140-3

Grounds the HSS-specific evidence requirements: required self-tests, LMS CAVP certificates, all HSS tree parameter sets, CSTL source-code review, Test Report documentation, and Security Policy tables.

NIST CAVP validation search

Use this public source to verify the underlying LMS algorithm certificate evidence referenced by an HSS vendor-affirmation claim.

FIPS 140-3 Vendor Affirmation

What evidence should teams keep for vendor affirmation?

Keep a compact evidence packet for each vendor-affirmed claim. It should identify the IG section, the module and version, the exact algorithm or key-generation method, the Security Policy table or disclosure, the CAVP certificates that remain required, and the CSTL or test-report evidence that the IG says must exist.

For SP 800-133 key generation, IG D.H says vendor affirmation is required for methods covered by Sections 4 and 6.3 when a symmetric key or seed for asymmetric key generation starts with a random bit string. It also says the Security Policy must provide details for each method, and that the validation certificate has a CKG entry only when the module generates keys for symmetric-key algorithms.

  • For HSS: keep the Vendor-Affirmed Algorithms table entry, Approved Algorithms table LMS entries, CAVP certificate references, CSTL source-code review record, and TE02.20.04 Test Report reference.
  • For SP 800-133: keep the Section 4 or Section 6.3 method mapping, DRBG-output explanation, independence rationale where relevant, CKG certificate-entry rationale, and Security Policy method details.
  • Set a review trigger when CAVP testing becomes available for a previously vendor-affirmed algorithm, because IG C.O points to the Management Manual transition process for moving from vendor affirmation to CAVP testing.
Citations
NIST CAVP validation search

Use this public source to verify algorithm certificate numbers that remain required even when a related vendor-affirmed claim is permitted.

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

Handle approved-mode claims at the service level

Start with the validated cryptographic module, not the product or platform around it. FIPS 140-3 specifies requirements for cryptographic modules, and CMVP guidance treats approved-mode analysis at the level of module services, security functions, indicators, and Security Policy descriptions.

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.

  • Map the claim to the validated cryptographic module boundary and the service table in the module Security Policy.
  • Classify each callable service as an approved security service, a non-security service allowed in approved mode, a non-approved algorithm with no security claimed, or a service not available in approved mode.
  • Use the module's service indicator, return code, status output, log message, or other externally accessible signal only if it lets the operator unambiguously determine when an approved security service is in use.
Citations
How should teams handle approved mode under FIPS 140-3?

What evidence supports an approved-mode answer?

The strongest evidence is the set of records that let a reader trace the answer from a module certificate and Security Policy to the exact service behavior. The CMVP guidance says the Security Policy must list approved and non-approved services with details and applicable indicators; the Security Policy can explain the indicators, but its text alone does not satisfy the indicator requirement.

Evidence should also show the treatment of non-approved algorithms. CMVP guidance allows some non-approved algorithms in approved mode only when no security is claimed and the use is documented in the Security Policy; non-approved security functions must not be used in approved mode.

  • Module certificate number, module name, version, operational environment, and security level claims for the validated configuration.
  • Security Policy service table showing approved and non-approved services, approved security service indicators, and any operator guidance needed to use a service in an approved manner.
  • Algorithm validation evidence for the approved security functions used by the claimed service, plus records showing required self-tests and approved parameters where applicable.
  • Configuration or runtime evidence showing that disallowed services are unavailable in approved mode and that non-approved algorithms with no security claimed are not presented as security functions.
Citations
NIST CAVP validation search

Public NIST search page for algorithm validation entries that can support service-level evidence when a FIPS 140-3 approved security service relies on a tested algorithm implementation.

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

What mistakes should teams avoid?

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.

  • Do not use a global approved-mode indicator by itself when the module can run approved and non-approved security services concurrently or when not all approved services are configured for the mode.
  • Do not rely on Security Policy narrative alone as the service indicator; the indicator must be externally accessible from the module's status interface and verifiable by the operator.
  • Do not call a non-approved cryptographic algorithm an approved-mode security function just because it is present while the module is in approved mode.
  • Do not reuse evidence from another certificate, module version, operational environment, or service table unless the validated boundary and configuration match the claim.
Citations
Page 2 of 2