Record each exhibit with its description and its SHA-256, then log every hand-off: who took it, from whom, when, and why. Export it as a printable custody record, a spreadsheet, or a file you can load back and carry on. A digest proves an exhibit has not changed. This is the part that says who was holding it while it did not. Kept in this browser, nothing uploaded.
No exhibits yet.
Attaching a file records its SHA-256 against the exhibit. The file itself is not stored anywhere, and it is not uploaded; only the digest is kept.
The export is the record, not this page. The log lives in this browser’s local storage, which means clearing site data, switching browsers or using a different machine loses it. Export after every session and keep the file where you keep the rest of the matter.
It makes the sequence explicit. Custody records fail in the gaps: an exhibit that moved without anybody writing it down, or a copy taken and never noted. Recording the hand-off as it happens, with the digest attached, closes those gaps while the detail is still fresh.
It is not a signature, and it is not a system of record. Nothing here stops somebody writing down something untrue, and the times come from the clock of the machine making the entry. It is a contemporaneous note kept properly, which is what a custody record has always been, not an attestation by a third party.
The digest is the part that is hard to argue with. If the exhibit at the end of the chain still matches the digest recorded at the start, it is byte for byte the same thing. If it does not, something happened, and the log narrows down where. PROOF runs that check for a whole set at once.
Nothing is uploaded. Files you attach are hashed in this tab and never leave it. The digest is kept; the file is not.