Historical evidence for PoTB

CommitteeHistory and HistoricalEvidence provide bounded historical authority for the upcoming PoTB inclusion profile. They do not activate penalties, change voting weights or admit validators in genesis versions 1 or 2.

HandoffVerifier now appends each outgoing committee only after the old quorum, exact ancestry, complete VRF transition and next-state witness authenticate. Failed handoffs leave both current authority and the history accumulator unchanged. This is local verifier state; the 50 frozen existing-profile wire fixtures still reproduce exactly. A future profile must explicitly commit the accumulator in its consensus state before validators can use it for canonical evidence inclusion.

Bounded historical authority

Tree shape and inclusion paths follow RFC 9162 section 2.1. The hash suite and wire formats are AstroLune-specific, not Certificate Transparency encodings. Separate BLAKE2s domains cover leaves, interior nodes, the empty tree and the final commitment. Leaves bind chain ID, genesis, exact height and committee root. The final commitment also binds the exact number of entries.

The frontier stores at most 64 hashes for a u64 height range. Count bits determine which peaks exist, so there is no alternate occupancy encoding. Updates require the next contiguous height and matching chain ID. Overflow or invalid coordinates leave the frontier unchanged. Decoding a frontier establishes structure only; a peer cannot make its own accumulator authoritative.

Proof construction reads historical roots exactly once in increasing height order, uses at most 64 recursive tree frames and 64 sibling hashes, and checks an explicit caller-supplied work limit before reading anything. It then compares the complete reconstructed tree with the trusted frontier. Corrupt/missing roots cannot produce a successful proof. This bounds memory, not the total number of historical reads; callers must set a suitable work limit.

Verification requires the shortest path for the exact count and height. Old-count, extra-node, changed-namespace and wrong-height proofs are rejected. A valid proof at one head does not claim validity against a newer head without updating its path.

Portable offence bundle

A bundle contains historical public keys and weights in committed seat order, the history proof and canonical DoubleVoteEvidence. Verification reconstructs the committee, proves that exact committee against independently authenticated history, then checks both conflicting signatures. Merely registering a key, leaving a committee or presenting a valid signature under another membership does not establish an offence at the requested height. Keys, weights and aggregate power must satisfy the existing strict committee rules.

The signing limitation described in document 25 remains: legacy votes bind chain ID and committee root, not genesis directly. Deployments must not reuse an identical legacy signing context and expect history wrappers to change what the original signatures signed.

Admission decision and activation work

For this closed network, admission is to require explicit authorization from the incumbent committee with voting power strictly greater than two thirds. This is the selected governance policy; a single administrator cannot substitute its signature for the quorum. The request, protected approval, certificate and operator CLI are implemented. The explicit PoTB producer profile now commits this history and implements canonical inclusion, active age weights and admission execution. Live daemon activation also provides authenticated evidence submission and gossip. Local observations and portable bundles outside finalized inclusion must not change consensus power.

Checks

Tests compare incremental roots with a separately structured recursive reference across balanced and unbalanced sizes and verify every leaf at selected boundaries through 257 entries. They cover full-width u64 counts, failed-update atomicity, work limits before reads, corrupt historical lookup, namespace/membership changes, all truncations and one-bit mutations, and historical evidence after an accused validator leaves the committee. The handoff tests also check authority/history rollback together through the verifier's complete equality checks.

The shared stable/libFuzzer oracle includes all three new formats, taking the structured corpus from 64 to 67 seeds. The repeated one-million-input deterministic campaign passed with 295,800 accepted decoder paths. This is not a coverage metric or a claim that active PoTB is complete.