Corona

Lux is not merely adding post-quantum signatures to a chain; it defines a hybrid finality architecture for DAG-native consensus, with protocol-agnostic threshold lifecycle, post-quantum threshold sealing, and cross-chain propagation of Horizon finality.

See LP-105 §Claims and evidence for the canonical claims/evidence table and the ten architectural commitments — single source of truth.

Corona is the Lux Ring-LWE post-quantum threshold signature library for Quasar consensus. The 2-round threshold construction line traces back to the Boschini–Kaviani–Lai–Malavolta–Takahashi–Tibouchi R-LWE paper (ePrint 2024/1113). Corona adds the production lifecycle that line lacked: Pedersen DKG over R_q with proper hiding, proactive resharing for epoch validator rotation, identifiable abort, and the integration surface Quasar consumes.

The Module-LWE sibling library lives at luxfi/pulsar. Pulsar's threshold signature output is byte-equal to FIPS 204 single-party ML-DSA (NIST MPTC Class N1). The two libraries are independent — there is no import line between them — and Quasar consumes them as parallel kernels selected per-chain via FinalitySchemeID.

Why "Corona"

A corona is the luminous ring of light surrounding a star — visible only when the brighter central body (the Pulsar / Quasar) is partially occluded. Brand-paired with Pulsar (Module-LWE) and Quasar (the consensus that consumes both): the same family of threshold-finality light, observed at a different layer.

Production lifecycle additions

The original Boschini et al construction (ePrint 2024/1113) is a research artefact — trusted-dealer DKG, no proactive resharing, no integration surface. Corona is the production track that fills those gaps:

Layer	Original R-LWE construction	Corona
2-round threshold sign	✅ same byte-equal protocol	✅ inherited
Trusted-dealer Gen	✅ for fixed federation	✅ retained for bridge MPC
Proactive resharing for epoch validator rotation	❌ not specified	🚧 corona/reshare/ (this fork)
Pedersen DKG over R_q with proper hiding	❌ not specified	🚧 corona/dkg2/ (this fork)
Per-validator triple-sign integration with Quasar	❌ N/A	🚧 corona/consensus/ integration

Composition with Pulsar as optional layered PQ defense

Corona is independently usable: a chain can pick Ring-LWE Corona as its sole PQ threshold layer, no cross-dependency on Pulsar. Lux primary- network QuasarCert combines both lattice families as a Double Lattice layered defence so a break in one family does not break finality:

QuasarCert {
    BLS         — optional classical fast-path (BLS-12-381 aggregate)
    Corona      — Ring-LWE   threshold ML-DSA (this repo)
    Pulsar      — Module-LWE threshold ML-DSA (luxfi/pulsar)
    MLDSARollup — per-validator ML-DSA-65 rolled up via STARK/FRI (P3Q)
}

Each layer is checkable independently with no shared code; selecting the layer happens at chain-construction time via the FinalitySchemeID axis on the chain's ChainSecurityProfile. The pure-PQ profile drops BLS entirely and runs on Corona + Pulsar.

Layout

• sign/ — 2-round threshold signing (byte-equal with upstream)
• primitives/ — Shamir, hashes, MACs, PRFs (byte-equal with upstream)
• utils/ — NTT, Montgomery, ring helpers (byte-equal with upstream)
• networking/ — TCP peer-to-peer (byte-equal with upstream)
• dkg/ — original Lux DKG (Feldman VSS without noise; broken for public broadcast — see RED-DKG-REVIEW). Retained for reference.
• dkg2/ — proper Pedersen DKG over R_q (Pulsar addition; this fork)
• reshare/ — proactive secret resharing for epoch rotation (Pulsar addition; this fork)
• cmd/ — KAT oracle generators

Status

WIP. The 2-round Sign+Verify path is byte-equal-validated against the original R-LWE construction (ePrint 2024/1113) via 16 SHA-256 KATs. The production-lifecycle additions (resharing + Pedersen DKG) are under design and implementation.