zeekay
4cff733804
FuzzPulsarSign1Round1Data found a 9-byte input that crashes the goroutine with `fatal error: out of memory: cannot allocate 105589698985984-byte block` in `lattice/v7/utils/structs.Vector[T]. ReadFrom`. Recovery cannot catch the fatal OOM — the only safe path is to reject malformed frames before `make([]T, size)` runs. This is a SECOND DoS surface in lattice/v7, distinct from the ReadUintNSlice recursion fixed by luxfi/lattice#3 (still open): ReadFrom calls `make([]T, size)` with `size` read from the wire before any bound check. PR #3 fixes the inner slice readers but the outer Vector wrapper allocation remains exploitable. Filed upstream as luxfi/lattice#4 with reproduction. The new validateVectorPolyFrameInline walker mirrors the existing warp/pulsar.validateVectorPolyFrame: walks the wire frame end-to-end, asserts every length field is <= MaxLatticeUintSliceLen (4096), and rejects truncated / over-large frames before the lattigo decoder runs. Result: FuzzPulsarSign1Round1Data passes 30s with the new walker in place (28577 execs, 0 panics). Failing input testdata/fuzz/FuzzPulsarSign1Round1Data/a80b8d313b40fa55 is now rejected cleanly with "vector length 70368955777453 exceeds 4096". Refs: luxfi/lattice#2 (open), luxfi/lattice#3 (open), luxfi/lattice#4 (filed 2026-05-04)
Pulsar
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.
Pulsar is the Lux-evolved post-quantum threshold signature stack for Quasar consensus, derived from daryakaviani/corona (academic 2-round threshold signature from LWE) with the protocol additions needed to operate on a leaderless open public chain.
Why "Pulsar"
Lux (Latin) → light. Pulsar → SI unit of luminous flux. Each validator emits a "pulsar" of signature toward consensus; aggregated, they form the chain's overall light. Brand-paired with Quasar (the consensus that consumes them).
Relationship to upstream Corona
The upstream repo at daryakaviani/corona is an academic proof-of-concept ("not ready for production use" per its README). Pulsar is the production track:
| Layer | Upstream Corona | Pulsar |
|---|---|---|
| 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 | 🚧 pulsar/reshare/ (this fork) |
| Pedersen DKG over R_q with proper hiding | ❌ not specified | 🚧 pulsar/dkg2/ (this fork) |
| Per-validator triple-sign integration with Quasar | ❌ N/A | 🚧 pulsar/consensus/ integration |
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 academic Corona spec via 16 SHA-256 KATs. The Pulsar-specific additions (resharing + Pedersen DKG) are under design and implementation.