Research-stage construction. Threshold hash-based PQ signature primitive over FIPS 205 SLH-DSA. Not production-ready. Not part of any current NIST submission. See DESIGN.md for the research direction and SUBMISSION-STATUS.md for the path to NIST MPTC v0.3.

Status

Field	Value
Standard	FIPS 205 SLH-DSA (single-party)
Threshold construction	Open research — no fixed protocol
Implementation	None
Submission package	Roadmap: NIST MPTC v0.3 target
Cert-profile role	Polaris profile in `luxfi/quasar` (cross-family PQ diversity)

Where this is used

The Magnetar leg of the Polaris cert profile in luxfi/quasar — the maximum-assurance cross-family profile that pairs lattice PQ (Pulsar M-LWE + Corona R-LWE) with hash-based PQ (Magnetar SLH-DSA). Polaris is the production migration target for when Magnetar matures.

Until Magnetar exists in production form, the Polaris profile is reserved but not deployable; production chains run the Pulsar or Aurora profile.

Why hash-based threshold matters

SLH-DSA's security rests on collision/preimage resistance of the underlying hash (SHA-2 or SHAKE), with no lattice assumption. A threshold profile of SLH-DSA gives cross-family defense in depth: even if a future cryptanalytic break hits the entire lattice family (both M-LWE and R-LWE), Magnetar's hash-based threshold leg keeps the cert sound.

Why it's hard

See DESIGN.md for the construction-level challenges. Summary: SLH-DSA does not decompose into a linear-aggregation identity the way ML-DSA does, so the FROST-style aggregation pattern that powers Pulsar/Corona doesn't transfer. Threshold SLH-DSA in the literature requires MPC over hash computations + per-signature MPC ceremony, which dominates deployment economics.

Cross-references

luxfi/quasar — umbrella spec; Magnetar is PRIMITIVES.md row
luxfi/pulsar — sibling threshold M-LWE primitive (production)
luxfi/corona — sibling threshold R-LWE primitive (production)

License

BSD-3-Clause. See LICENSE.

Maintainer

magnetar@lux.network — Lux Industries, Inc.