Implemented the remaining STM verification layers:
- internal/stm/lottery.go: EvaluateSigma (Blake2b-512 lottery draw) +
IsLotteryWon with Taylor-series threshold comparison (ported from
mithril-stm::eligibility), big.Rat-based to match Rust's num_bigint/
num_rational path
- internal/stm/merkle.go: Blake2b-256 Merkle batch-proof verification,
faithful port of mithril-stm's verify_leaves_membership_from_batch_path
including the 'current is left/right child' branch logic and the
1-byte zero pad for missing siblings
- internal/stm/verify.go: top-level stm.Verify(msg, ms, avk, params)
glues all four checks: k-threshold, lottery, Merkle, BLS aggregate
- cmd: 'verify head' now runs full STM verification; JSON output shows
signers, wins, params, verified flag
- MCP: new 'mithril_verify_certificate' tool dispatches genesis Ed25519
vs STM by cert kind
Verified against live networks:
mainnet head cert bc00b551… epoch=626 59 signers 1972/16948 wins ✓
mainnet genesis 25acfcfe… epoch=539 Ed25519 ✓
preprod head dd9c4fcb… epoch=284 2 signers 11/100 wins ✓
preprod genesis 69bc3bdf… epoch=196 Ed25519 ✓
This is a consensus-correct pure-Go Mithril client. Single binary,
CGo-free, no upstream Rust dependency.
Next: full chain verification (walk head → genesis, check continuity).