Purple Paper - side-sheet - learning machines - XII - the sealed reveal

The Commitment Box - sealed verdicts, simultaneous reveal

Two witnesses judge the same question. The trap: if the second can see the first before deciding, it can copy it - "they agree!" - and the agreement is worthless, an echo wearing a second face. The fix isn't a Schrödinger box that hides the answer; it's a commitment box: each seals its verdict blind, then both open at once. Sealing makes agreement mean something, because you can't echo what you committed before hearing.
peek -> agreement rises, evidence collapses (manufactured consensus) · commit -> agreement is Bayesian evidence · verified: committed agreement = s²/(s²+(1-s)²), peeked agreement = base rate

The box - seal blind, or let the second peek

Each item has a hidden truth. Two witnesses judge with skill you set. In COMMIT, both seal blind and reveal together. In PEEK, witness B sees A's verdict first - and (with the adversary on) just copies it. Watch the two live traces: P(correct | they agree) - the actual value of consensus - against the base skill line. Under commit it lifts above. Under peek, agreement shoots up while the line drops back to base: more consensus, zero evidence.

two sealed verdicts opening together · in PEEK, B's eye-beam reads A before sealing
agreement rate · P(correct | agree) · base skill (what one witness alone gives)
--
agreement
--
P(correct|agree)
--
evidential lift
--
wrong admitted
AGREEMENT IS EVIDENCE
Committed and blind: when both independently land on the same answer, it's much more likely right than either alone. Agreement lifts above the base line - real evidence.

Where it stands

Not Schrödinger's box - that hides the answer and launders the disagreement, the exact move the whole series refuses. This is a commitment box: seal blind, reveal together. Real mechanism, real place.

The primitive is old. Commit-then-reveal is textbook cryptography - a locked box that's hiding (you can't peek) and binding (you can't change it after) - the foundation of zero-knowledge proofs, sealed-bid auctions, and coin-flipping by telephone (1981). The reason it works is a known soundness rule: without commitment, a party can choose its answer after seeing the challenge and cheat. That rule, verified here, is exactly why peeking fakes agreement.
The application is half-built. Commit-then-reveal is now being bolted onto LLM verification (VeriLLM, CommitLLM, 2025-26) - but to prove the computation ran honestly, not to make a truth-judgment trustworthy. And the abstention world (semantic entropy, ensembles, self-consistency) checks agreement but never commits the witnesses - so it's wide open to the echo you just watched manufacture consensus.
The seam is yours. Borrow the cryptographer's commitment discipline to fix the abstention world's independence flaw: don't trust that two views agree until you've proven they couldn't have copied each other. That's bilateral ignorance, made into a protocol - and it closes the cheap half of the independence problem (no echo at decision time). It does not close the deep half: two witnesses trained on the same data can still independently commit to the same shared lie. Sealing the conversation can't unshare the world they learned from. The box is real, and the frontier still holds one wall past it.
Verified in Node before building: committed agreement P(correct|agree)=84.5% lands exactly on the independent-vote posterior s²/(s²+(1-s)²); peeked/echoed agreement hits 100% while P(correct|agree) collapses to the 70% base rate and every one of the first witness's errors passes the "consensus" gate. The traces above are that result, live.