What Is FIPS 206 / FN-DSA? A Plain-English Guide to FALCON Signatures
FIPS 206, also called FN-DSA or FALCON, is a quantum-safe digital-signature standard under development at NIST. Learn how FALCON works, where it fits with ML-DSA and SLH-DSA, and whether your business needs it.
NIST finalized three post-quantum standards in August 2024: FIPS 203 for key encapsulation, and FIPS 204 and 205 for digital signatures. FN-DSA, based on FALCON, remains under development as FIPS 206.
The FALCON design in one paragraph
FALCON is a lattice-based signature algorithm selected by NIST for standardization. Its compact signatures make it worth evaluating when transmission or storage costs matter. Selection is not the same as a finalized standard or validation of a particular implementation.
How FIPS 206 fits with FIPS 204 and 205
ML-DSA (FIPS 204) and SLH-DSA (FIPS 205) are finalized signature standards. FN-DSA is an additional option being developed. FIPS 203 specifies ML-KEM for establishing shared keys; it is not a signature standard.
Where FALCON may help
Evaluate compact signatures against your actual bandwidth, storage, signing hardware and verification workload. Benchmark the exact implementation and parameter set rather than assuming one algorithm is always fastest.
Planning with finalized standards
Start migration planning with the published standards and your protocol requirements. Confirm library support, interoperability and any required module validation before selecting a deployment.
Development status — checked October 20, 2026
FIPS 206 was not published alongside the three final 2024 standards. In a September 28, 2026 update, NIST's FIPS 206 team described plans to produce a draft using fixed-point arithmetic for key generation and signing, with detailed signing procedures supporting known-answer testing. Those are development plans, not a final specification.
Should your business adopt FALCON now?
Keep evaluation work separate from production commitments that require a finalized standard. Inventory existing signatures, identify interoperability constraints, and track NIST's publication updates before committing to FN-DSA requirements.
FAQ
Is FIPS 206 finalized?
No. NIST lists FALCON standardization as ongoing. Its September 2026 update discusses plans for a draft.
Can I combine signature algorithms?
Support depends on the protocol, signature format and implementations at both ends. Do not assume algorithms can be combined or negotiated without explicit support.
Plan around verified requirements
Track FN-DSA as a developing option while planning migration around published standards and tested integrations.
Primary sources
- NIST post-quantum cryptography project and standards status
- NIST FIPS 206 team: New plan for FN-DSA, September 28, 2026
Want to see which parts of your infrastructure still rely on classical signatures? Run Secuur's free quantum-risk scan and get a prioritized migration checklist.