@mikeargento/exam-bank

The question bank of the sealed exam: five deterministic generators (multi-step arithmetic, a seating puzzle with a solver-enforced unique answer, a string-transformation pipeline, a small JavaScript specification checked on hidden inputs, an ordering task over generated facts), each drawing its instances from a DRBG seeded by BitGraph A's nonce (the bind that opens every sitting, of a request naming this bank; a slot commitment for the archived sittings). bank.json is the canonical bank document; its digest is what A's request and every paper name. proof/ is the bank's first BitGraph, recorded on 12 September 2026, before any paper.

The derivation, with vectors, is SPEC.md in @mikeargento/exam-core. Used by @mikeargento/exam-cli.

src/ is frozen

src/** (the thirteen files listed by tar -tf <sitting>/bank/generator.tar) is archived verbatim into every recorded sitting and hashed into the bank digest, which the paper names and the verifier recomputes. Editing any byte of src/ invalidates every sitting ever recorded, including every one in this repository: the verifier stops being able to re-derive their papers and reports NO-EVIDENCE for all of them.

That is the mechanism working, not a bug. It also means the ordinary housekeeping edit is not ordinary here. On 2026-09-14 a copyright-holder sweep rewrote the header of all thirteen files and every sitting in the package went NO-EVIDENCE; the headers still read the holder they were sealed with, and they have to. LICENSE and package.json are NOT in the archive and can be changed freely.

To change anything under src/, every sitting has to be re-run with the new bank. Nothing else does.