Documentation
What is a capsule?
A capsule is a fingerprint of your work, signed by you. It is what gets published — never the work itself.
When you protect something, your device reads the file and computes a set of measurements from it: a cryptographic hash of the exact bytes, perceptual hashes that survive cropping and re-encoding, a tiled fingerprint, and — for images and video — a semantic descriptor that recognises the same subject even after heavy editing.
Those measurements are gathered into a capsule, signed with your key, and registered. The file stays on your device. Nothing about it is uploaded.
It only goes one way
A capsule cannot be turned back into the work it describes. That is not a policy — it is a property of the mathematics. A hash discards information by design, and no amount of computation recovers what was discarded.
What a capsule can do is settle a question: does this file I am looking at match something that was registered, and when was it registered, and by whom.
What is actually published
The capsule and its signature. Roughly four kilobytes. Anyone can fetch it, and anyone can check the signature against your public key without your involvement and without an account.