LPsLux Proposals
Post-Quantum Cryptography
LP-4520

SLH-DSA-192 (FIPS 205 Level 3) Parameter Tier — Network Default

Draft

Parameter-tier sub-spec for SLH-DSA-192 (NIST FIPS 205 security level 3), the Lux network default hash-based signature. Algorithm definition deferred to LP-4500.

Category
Core
Created
2026-05-18

Implementation status (code-audited 2026-07-03): SHIPPED Parameters confirmed against luxfi/crypto/slhdsa (circl v1.6.3).

Abstract

SLH-DSA-192 is the NIST FIPS 205 security-level-3 parameter family of the Stateless Hash-based Digital Signature Algorithm and the Lux network default for hash-based signatures (precompile address 0x012203 in LP-0120 uses SLH-DSA-192f). This LP pins the tier identifier, covers both the "s" (small, ~16 KB sig) and "f" (fast, ~35,664 B sig) sub-variants, and points at the algorithm spec in LP-4500. Sizes: public key 48 B, secret key 96 B. Verification time ~1.92 ms (131 µs cached). Use SLH-DSA-192 for conservative defense-in-depth alongside ML-DSA-65 (LP-4420) on long-lived signing keys, audit trails, and cert profiles requiring hash-only security assumptions.

Reference implementation

  • Primitive: luxfi/crypto/slhdsa/slhdsa192
  • Hash backend: SHA2-384 or SHAKE192
  • Threshold wrapper (Magnetar): LP-4540
  • Test vectors: NIST KAT vectors (FIPS 205 Appendix B)

Provenance

Originally LP-4420, renumbered 2026-05-18 to consolidate all cryptographic primitives into the 4xxx range with family sub-ranges (PQ hash signatures 4500-4599). The 4420 slot is retained as a permanent pointer to this LP.

Copyright and related rights waived via CC0.