wai-mark:tent64: the second marking layer, a watermark recomputed from its payload, read with no key, measured against an attack battery (SYN-2) #407

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dcharlot merged 10 commits from wai/synthesis-mark into main 2026-10-22 00:11:35 -04:00

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2026-10-21

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Merge origin/main into wai/synthesis-mark ...

Co-Authored-By: Claude Opus 5.5 <[email protected]>

b0d1a3a492

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2026-10-21 23:53:24 -04:00

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Merge origin/main into wai/synthesis-mark (room e2e window wait) ...

Co-Authored-By: Claude Opus 5.5 <[email protected]>

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2026-10-21 20:38:40 -04:00

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Merge origin/main into wai/synthesis-mark (settlement, contribution, shared lists) ...

Co-Authored-By: Claude Opus 5.5 <[email protected]>

fd258dfbcf

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2026-10-21 19:24:46 -04:00

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Merge remote-tracking branch 'origin/main' into wai/synthesis-mark

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2026-10-21 14:42:30 -04:00

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synthesis.md §7: wording of the definition's line breaks, the floor's bound and the decoder; clippy on the scheme's tables and luma ...

Co-Authored-By: Claude Opus 5.5 <[email protected]>

288a8a9e30

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2026-10-21 13:53:51 -04:00

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wai-mark:tent64: registry, SPEC §5, CHANGELOG, CI step, corpus README ...

The wire identifiers wai-mark:tent64 and wai-mark:conformance (schemes, §7.4) and
/.well-known/wai-mark/ (proposed, §7.7); the registry export regenerated. A CI
step runs the scheme's unit tests, tests/synthesis_mark.rs in release and
synthesis_mark_verify.py. The corpus README states its provenance and names the
photographs of §7.5.8's informative column by SHA-256.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

584225862e

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2026-10-21 13:29:05 -04:00

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synthesis.md §7: the registered scheme wai-mark:tent64, what it survives, its signpost and resolver; the second implementations ...

§7.4 registers wai-mark:tent64 by its definition and digest and keeps
wai-mark:conformance as the scheme with no algorithm. §7.5 is the scheme: frames
and luma, the grid and the tent pattern, the stream, the shuffle, the signs and
the mask, the shortened BCH code, the informed embedding, the detector in eight
orientations, what it guarantees (no other channel, a PSNR floor, a
false-positive bound derived and checked), the battery and the table of what it
survives, with the claims it makes. §7.6 proves a marking by recomputation and
reproduces a detection; §7.7 gives the signpost in the content and in the C2PA
statement, and a well-known resolver; §7.8 has a sink that generates mark as part
of the reconstruction it is held to. _wai_mark.py is the scheme and the battery
in Python from the text; synthesis_verify.py runs §7.6's checks with it;
synthesis_mark_verify.py verifies the scheme's corpus, mutates it and weakens
itself in turn.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

7f08895096

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2026-10-21 13:25:42 -04:00

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synthesis_mark: the scheme's attack battery, measurement sets and conformance corpus ...

The battery applies the crate's own integer codecs (wai.video.int_motion's
encoder, a staged base through wai-synthesis:upscale2), the pinned derivations
of §4, area resampling, crops, quarter turns and mirrors, small rotations,
noise from a fixed stream, brightness, contrast and a local blur, each an
integer function of the frames. The measurement sets are generated from fixed
seeds: wai.generate.spectral's generator with its committed model, and a
dead-leaves generator. The corpus holds the scheme's definition, the code's
words, embeddings and detections over stored frames, a battery sample, cases
whose markings are recomputed and detections run again, and the measurement.
The amplitude cap is 12: at 8 the most textured photographs left bits short.
A conversion's detection agrees with the claim it inherits the mark from.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

8738f841e7

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2026-10-21 13:05:17 -04:00

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synthesis: markings and detections of the registered scheme are recomputed and run again ...

A marking states the frames it embedded into (their size and the digests of the
unmarked and the marked frames) and a detection the frames it read. Holding the
unmarked frames, a verifier recomputes the marking's derivation; holding the
decoded frames, it runs the detector again. New codes: scheme_mismatch,
mark_evidence_invalid, mark_input_mismatch, mark_recompute_mismatch,
detection_irreproducible, layer_not_proved; a policy member second_layer; each
marking states its C2PA signpost. The synthesis corpus regenerates with the new
members and gives the codes that need no frames.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

88ecfcd753

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2026-10-21 12:42:22 -04:00

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synthesis: the watermark scheme wai-mark:tent64, embedded by a pinned integer derivation and read with no key ...

A tent checkerboard in each cell of a 64 x 64 grid that follows the picture
through a rescale; a public stream shuffles the cells, signs them and masks the
code; the 8-byte payload is a BCH(255, 71) codeword shortened to 248 bits, each
bit carried by 16 cells; each bit is given the least amplitude up to 8 that
gives its statistic the sign the codeword asks with a margin of 3/2 of its
weight mass. The detector reads the signs in each of the 8 orientations and
decodes up to 29 errors.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

c8c8b05335

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2026-10-21 12:38:28 -04:00