FN-DSA (Falcon)

Type

Digital signature

Family

Lattice (NTRU, fast-Fourier sampling)

Standard

FIPS 206 (draft)

Standardized by

NIST

Date

TBD (draft under review; final expected late 2026 or 2027)

Status

Draft

Last reviewed 2026-09-12 by the PQC Audit Index editors.

Parameter sets and sizes (bytes)

NIST security categories: 1 ≈ AES-128, 2 ≈ SHA-256 collision, 3 ≈ AES-192, 5 ≈ AES-256.

Where FN-DSA is deployed

• Blockchains and constrained protocols that need the smallest post-quantum signatures (about 666 bytes at category 1)
• Not yet approved for FIPS 140-3 validation until FIPS 206 is final

What an audit of FN-DSA checks

• The floating-point Gaussian sampler is the hardest part of any post-quantum standard to implement in constant time; audit emulated-FP paths and every platform-specific FPU behavior
• Key generation (NTRU solve) correctness and secret-dependent timing
• Signature encoding and the variable-length compression format
• Reference implementations still change between draft versions; verify against the exact draft the project targets

See the full post-quantum cryptography audit checklist.

Who audits FN-DSA implementations

Firms with a cryptography practice that review FN-DSA implementations and protocol integrations, in the order this index lists them:

1. zkSecurity — Cryptography audits: post-quantum, zero-knowledge proofs, MPC, FHE, TEEs
2. Trail of Bits — Software assurance with a dedicated cryptography practice
3. NCC Group (Cryptography Services) — Large security consultancy with a specialist Cryptography Services team
4. Cryspen — Formally verified cryptography and high-assurance post-quantum implementations
5. Kudelski Security — Cryptography audits and quantum-readiness assessments
6. Quarkslab — Reverse engineering, cryptography, and secure implementation research
7. Least Authority — Security audits of cryptographic protocols and privacy-preserving systems
8. Galois — Formal verification of cryptographic code
9. atsec information security — FIPS 140-3 and CAVP validation laboratory
10. Riscure (Keysight) — Side-channel and fault-injection evaluation of hardware implementations
11. Cure53 — Penetration testing and code audits of open-source and web software
12. X41 D-Sec — Source-code audits of open-source security and cryptographic software

Primary sources

• NIST PQC standardization project page
• FIPS 206 status update (NIST, 2025)
• Falcon specification

Machine-readable: data.json · summary.txt