--- title: "FIPS-approved cryptographic algorithms FAQ" canonical_url: "https://www.sorena.io/artifacts/global/fips-crypto-algorithms/faq" source_url: "https://www.sorena.io/artifacts/global/fips-crypto-algorithms/faq/items/page/2" author: "Sorena AI" description: "Answers to common FIPS algorithm questions: approved security functions, CAVP validation, CMVP module scope, AES modes, SHA-2, SHA-3, signatures, and post-quantum algorithms." published_at: "2026-05-09" updated_at: "2026-07-25" keywords: - "FIPS algorithms" - "CAVP validation" - "CMVP validation" - "AES" - "SHA-2" - "SHA-3" - "ML-KEM" - "ML-DSA" - "CAVP" - "CMVP" - "post-quantum cryptography" --- **[SORENA](https://www.sorena.io/)** - AI-Powered GRC Platform [Home](https://www.sorena.io/) | [Solutions](https://www.sorena.io/solutions) | [Artifacts](https://www.sorena.io/artifacts) | [About Us](https://www.sorena.io/about-us) | [Contact](https://www.sorena.io/contact) | [Portal](https://app.sorena.io) --- # FIPS-approved cryptographic algorithms FAQ Answers to common FIPS algorithm questions: approved security functions, CAVP validation, CMVP module scope, AES modes, SHA-2, SHA-3, signatures, and post-quantum algorithms. *FAQ* *GLOBAL* *FIPS-approved cryptographic algorithms* ## FIPS-approved cryptographic algorithms FAQ Answers to practical questions about approved algorithms, CAVP certificates, CMVP module validation, approved mode, and algorithm evidence. This page helps separate standards facts from vendor claims, procurement language, and product-specific validation evidence. FIPS-approved algorithm questions often get blurred with FIPS 140-3 module claims. This FAQ separates the layers: a cryptographic algorithm may be specified in a FIPS publication, adopted in a NIST recommendation, or listed as an approved security function, while a product claim usually depends on the cryptographic module boundary, the services used in approved mode, and the validation evidence available for the implementation. ## Definitions ### FIPS-approved cryptography **Term:** FIPS-approved FIPS-approved describes an exact cryptographic algorithm, technique, or service that current FIPS 140-3 approved-security-function sources permit for the stated use and parameters. It does not mean that every implementation, protocol, product, or cloud service using that name has passed CAVP testing or CMVP module validation. **Why it matters here:** A defensible claim names the governing source, algorithm or scheme, mode or parameter set, intended operation, tested implementation, and validated module boundary when module validation is asserted. Sources: - [NIST FIPS 140-3 security requirements for cryptographic modules](https://csrc.nist.gov/pubs/fips/140-3/final?ref=sorena.io) ### Cryptographic Algorithm Validation Program **Term:** CAVP CAVP is NIST's program for validation testing of approved cryptographic algorithm implementations and individual components. A public listing identifies the vendor, implementation, tested operational environment, validation date, and algorithm details. **Why it matters here:** Use CAVP evidence for an implementation-level algorithm claim. It does not establish that the containing product or cryptographic module is FIPS 140-3 validated. Sources: - [NIST Cryptographic Algorithm Validation Program](https://csrc.nist.gov/projects/cryptographic-algorithm-validation-program?ref=sorena.io) ### Cryptographic Module Validation Program **Term:** CMVP CMVP is the NIST and Canadian Centre for Cyber Security program that validates cryptographic modules against FIPS 140-3 and related requirements. A validation applies to the named module, version, boundary, tested configuration, security level, and documented services. **Why it matters here:** Use CMVP evidence for module-level and approved-mode claims. A CAVP certificate or an algorithm name cannot replace the module certificate and Security Policy. Sources: - [NIST Cryptographic Module Validation Program](https://csrc.nist.gov/projects/cryptographic-module-validation-program?ref=sorena.io) ### Approved mode of operation **Term:** approved mode Approved mode is a cryptographic module state in which the module provides claimed security through approved security services, or through services the CMVP rules expressly allow under stated conditions. The module must indicate whether the service being invoked is approved. **Why it matters here:** A product does not operate in approved mode merely because it contains an approved algorithm. The service, parameters, module boundary, indicator, and Security Policy conditions must match. Sources: - [CMVP Implementation Guidance for FIPS 140-3](https://csrc.nist.gov/csrc/media/Projects/cryptographic-module-validation-program/documents/FIPS%20140-3/FIPS%20140-3%20IG.pdf?ref=sorena.io) ## Browse sub-FAQ modules ### [FIPS 203, 204, and 205 Post-Quantum Algorithms](/artifacts/global/fips-crypto-algorithms/faq/fips-203-204-and-205-post-quantum-algorithms.md) FAQ on how FIPS 203 ML-KEM, FIPS 204 ML-DSA, and FIPS 205 SLH-DSA fit FIPS-approved cryptographic algorithm planning, implementation evidence, and validation checks. - 3 items ### [FIPS Algorithm Procurement Evidence FAQ](/artifacts/global/fips-crypto-algorithms/faq/procurement-evidence.md) What procurement teams should collect before accepting FIPS algorithm or module claims: CAVP certificates, CMVP module status, security policy scope, and supplier change triggers. - 3 items ### [FIPS validation certificates for cryptographic algorithms](/artifacts/global/fips-crypto-algorithms/faq/validation-certificates.md) How to read CAVP algorithm validation certificates and CMVP module validation certificates without overstating FIPS-approved cryptographic algorithm claims. - 4 items ### [How FIPS 180-4 and FIPS 202 Hash Functions Fit FIPS Algorithm Approval](/artifacts/global/fips-crypto-algorithms/faq/fips-180-4-and-fips-202-hash-functions.md) Identify SHA-1 and SHA-2 in FIPS 180-4 and SHA-3 and SHAKE in FIPS 202, then check current-use status and CAVP/CMVP evidence separately. - 3 items ### [How FIPS 186-5 Signature Algorithms Fit FIPS Approval](/artifacts/global/fips-crypto-algorithms/faq/fips-186-5-signatures.md) Use FIPS 186-5 for RSA, ECDSA, deterministic ECDSA, EdDSA, HashEdDSA, DSA verification limits, approved hashes, and CAVP/CMVP evidence boundaries. - 3 items ### [What does FIPS 197 AES mean for FIPS-approved algorithms?](/artifacts/global/fips-crypto-algorithms/faq/fips-197-aes.md) FIPS 197 defines AES as a FIPS-approved block cipher, but AES use alone is not the same as CAVP algorithm testing or FIPS 140-3 module validation. - 3 items Browse all indexed questions: [/artifacts/global/fips-crypto-algorithms/faq/items](/artifacts/global/fips-crypto-algorithms/faq/items.md) ## All FAQ items *Page 2 of 2. Showing 4 of 19 items.* ### [What FIPS 186-5 signature mistakes should teams avoid?](/artifacts/global/fips-crypto-algorithms/faq/fips-186-5-signatures.md#what-fips-186-5-signature-mistakes-should-teams-avoid) *Module: [How FIPS 186-5 Signature Algorithms Fit FIPS Approval](/artifacts/global/fips-crypto-algorithms/faq/fips-186-5-signatures.md)* Do not reuse signature keys. FIPS 186-5 says digital signature key pairs must not be used for other purposes such as key establishment, and it repeats that RSA and ECDSA signature keys are signature-only. A key inventory should therefore show a signature-only purpose rather than a shared public-key bucket. - Do not use a signature key pair for key establishment, encryption, or other non-signature purposes. - Do not claim DSA signature generation as approved under FIPS 186-5; limit DSA to the legacy verification context supported by the standard. - Do not reuse a CAVP certificate across a different implementation, version, operating environment, parameter set, or module boundary without confirming the scope. Sources for this answer: - [NIST FIPS 186-5 Digital Signature Standard](https://doi.org/10.6028/NIST.FIPS.186-5?ref=sorena.io) - Supports key-purpose separation, assurance checks before accepting signatures as valid, and the limits of conformance claims. - [NIST FIPS 140-3 Implementation Guidance](https://csrc.nist.gov/CSRC/media/Projects/cryptographic-module-validation-program/documents/fips%20140-3/FIPS%20140-3%20IG.pdf?ref=sorena.io) - Clarifies that approved-service indicators may depend on the signature algorithm, hash algorithm, and key size used by the service. ### [What does FIPS 197 actually define?](/artifacts/global/fips-crypto-algorithms/faq/fips-197-aes.md#what-does-fips-197-actually-define) *Module: [What does FIPS 197 AES mean for FIPS-approved algorithms?](/artifacts/global/fips-crypto-algorithms/faq/fips-197-aes.md)* FIPS 197 defines the Advanced Encryption Standard as a symmetric block cipher for protecting electronic data. The standard specifies three AES variants: AES-128, AES-192, and AES-256. - Use FIPS 197 to identify the AES algorithm family and the allowed AES key sizes. - Record the AES mode separately because FIPS 197 says AES shall be used with a FIPS-approved or NIST-recommended mode of operation. - Do not describe Rijndael options outside AES-128, AES-192, or AES-256 as FIPS 197 AES. Sources for this answer: - [NIST FIPS 197-upd1 Advanced Encryption Standard](https://doi.org/10.6028/NIST.FIPS.197-upd1?ref=sorena.io) - Defines AES as the FIPS-approved algorithm and specifies AES-128, AES-192, AES-256, 128-bit blocks, and approved or recommended mode usage. - [NIST block cipher modes project](https://csrc.nist.gov/projects/block-cipher-techniques/bcm/current-modes?ref=sorena.io) - Identifies the NIST SP 800-38 mode publications used to select and document an AES mode for a specific service. ### [Does using AES mean a module is FIPS validated?](/artifacts/global/fips-crypto-algorithms/faq/fips-197-aes.md#does-using-aes-mean-a-module-is-fips-validated) *Module: [What does FIPS 197 AES mean for FIPS-approved algorithms?](/artifacts/global/fips-crypto-algorithms/faq/fips-197-aes.md)* No. FIPS 197 defines the AES algorithm; it is not a cryptographic module certificate. A product can use AES while still needing separate evidence about the implemented algorithm, module boundary, operational environment, approved services, and FIPS 140-3 validation status. - Treat an AES library name, marketing claim, or source-code reference as insufficient by itself. - Confirm the tested AES implementation, mode, key sizes, certificate identifier, vendor, version, and operational environment in the applicable CAVP or CMVP record. - When the claim is about FIPS 140-3, tie the AES evidence to the validated cryptographic module boundary rather than to the surrounding application alone. Sources for this answer: - [NIST CAVP validation search](https://csrc.nist.gov/projects/cryptographic-algorithm-validation-program/validation-search?ref=sorena.io) - Public NIST search page for locating algorithm validation records such as AES implementation certificates. - [NIST FIPS 140-3 security requirements for cryptographic modules](https://doi.org/10.6028/NIST.FIPS.140-3?ref=sorena.io) - Defines security requirements for cryptographic modules and separates module validation from the AES algorithm specification. - [CMVP Implementation Guidance for FIPS 140-3](https://csrc.nist.gov/csrc/media/Projects/cryptographic-module-validation-program/documents/FIPS%20140-3/FIPS%20140-3%20IG.pdf?ref=sorena.io) - Explains that CMVP validates cryptographic modules and CAVP addresses testing of approved security functions referenced by FIPS 140-3. ### [What decision sequence should an AES review follow?](/artifacts/global/fips-crypto-algorithms/faq/fips-197-aes.md#what-decision-sequence-should-an-aes-review-follow) *Module: [What does FIPS 197 AES mean for FIPS-approved algorithms?](/artifacts/global/fips-crypto-algorithms/faq/fips-197-aes.md)* Start with the security service and controlling protocol, not the AES label. Decide whether the design needs confidentiality only, authenticated encryption, storage encryption, or key wrapping; identify the NIST mode and protocol profile that permits that service; then record the AES key size, mode parameters, key source, implementation version, and deployment environment. - Example: use an approved GCM implementation when the controlling protocol permits authenticated encryption and the design can meet that profile's nonce and tag requirements; do not infer those requirements from FIPS 197. - Example: a legacy CBC service needs its own approved-mode, IV, padding, integrity, and protocol analysis; an AES-CBC algorithm entry alone does not prove the complete service is secure or validated. - Outcome: approve the scoped service only when the algorithm, mode, parameters, implementation, operational environment, and module evidence all match; otherwise record the gap and the owner responsible for remediation or an alternative design. Sources for this answer: - [NIST FIPS 197-upd1 Advanced Encryption Standard](https://doi.org/10.6028/NIST.FIPS.197-upd1?ref=sorena.io) - Defines the AES variants and requires use with an approved or NIST-recommended mode of operation. - [NIST block cipher modes project](https://csrc.nist.gov/projects/block-cipher-techniques/bcm/current-modes?ref=sorena.io) - Official index for selecting the NIST mode publication that controls confidentiality, authenticated encryption, storage encryption, or key wrapping. - [CMVP Implementation Guidance for FIPS 140-3](https://csrc.nist.gov/csrc/media/Projects/cryptographic-module-validation-program/documents/FIPS%20140-3/FIPS%20140-3%20IG.pdf?ref=sorena.io) - Supports matching algorithm evidence, approved services, implementation versions, and tested operational environments to a module claim. ## FAQ Pagination - Canonical index (page 1): [/artifacts/global/fips-crypto-algorithms/faq/items](/artifacts/global/fips-crypto-algorithms/faq/items.md) - Page 1 rule: `/page/1` is intentionally not generated; use the canonical index markdown URL. - Current page: 2 of 2 Pages: [1](/artifacts/global/fips-crypto-algorithms/faq/items.md) | [2](/artifacts/global/fips-crypto-algorithms/faq/items/page/2.md) [Previous page](/artifacts/global/fips-crypto-algorithms/faq/items.md) *Recommended next step* *Placement: after FAQ answers* ## Turn FIPS algorithm questions into verifiable evidence Use the cited standards, CAVP records, CMVP certificate data, and Security Policy language to keep algorithm claims precise before they reach customers, auditors, or procurement teams. - [Open Assessment Autopilot for FIPS evidence](/solutions/assessment.md): Convert FIPS algorithm and module evidence into owned tasks, evidence requests, and review checkpoints. - [Research FIPS source questions](/solutions/research-copilot.md): Resolve CAVP, CMVP, approved-mode, and algorithm-standard questions against cited source material. - [Review a FIPS claim with Sorena](/contact.md): Check whether customer-facing wording matches the underlying algorithm, module, and validation evidence. --- [Privacy Policy](https://www.sorena.io/privacy.md) | [Terms of Use](https://www.sorena.io/terms-of-use.md) | [DMCA](https://www.sorena.io/dmca.md) | [About Us](https://www.sorena.io/about-us.md) (c) 2026 Sorena AB (559573-7338). 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