Forensic mark — signs of editing

A helper mark that helps find signs of cutting, pasting or editing. It is not grounds for pointing at a specific person. We don't use the non-commercial TruFor; we use Apache-2.0 Sigil.

Experimental · not for legal attribution

Tracking rate and false accusation rate by conspirator count are not measured. Those rates are not used in marketing until they exist. The plan is to record correct traces and wrong accusations separately for each conspirator count.

Plain words · exact workings

Signs of tampering (forensic mark)

Closer to a ‘clear sticker’ that helps find where something was cut and pasted. It cannot point to who did it.

The simple story

A secret pattern P is mixed very faintly into the original.
Cutting with scissors or applying a strong filter breaks the pattern.
The detector scores ‘how much of the pattern is left’ and draws a tamper map.

How it works, exactly

Result ≈ original + α·P. Score ≈ correlation(result, P).
A high score means close to the original; a low score means it was likely altered.
XenLook uses Sigil (Apache-2.0, commercial use allowed) and does not use TruFor (non-commercial).

Easy to mix up

Its purpose differs from a watermark (planting an ID). Forensics is closer to ‘detecting tampering’.

Pick an image sample, then check the chips to see where the forensic step sits in the pipeline.

Demo · see it for yourself

Samples you can try

Play photos, video, music and documents, take their fingerprint number, and check their Content Credentials (C2PA). XenLook holds thousands of character media files; these few samples were picked to show the idea and the check simply.

The invisible stamp

Left and middle look the same to the eye. Right is a magnifier that blows ε up 40×.

what you see ≈ original + ε

Real VideoSeal encoding uses a smarter pattern. This is a lesson in why it stays invisible.

1 Watermark

What XenLook does

Sigil Watermark (Apache-2.0) is wired in as the first choice for the forensic step. Encoding works once its dependencies (reedsolo and others) are installed.

Open source we use (commercial use OK)

Sigil Watermark — Apache-2.0. Pixseal (Apache-2.0) as a backup. WAM with MIT weights only. TruFor is not allowed.

Sigil (Apache-2.0)

XMSE status (this step)

Item	Status	Note
Sigil OSS chosen	Applied	Apache-2.0
Pipeline link	Connected (unverified)	embed PASS · collusion tracing rate not measured
TruFor removed	Applied	policy lock

Demo studio → Full XMSE stack NFT and blockchain status C2PA generator →