Check a record pack

Choose the pack

The record pack (the .zip file) Or the unzipped folder (the folder that holds record.json) Bitcoin block headers (optional: a .json file, to check the Bitcoin block without a connection) Also look up the Bitcoin blocks online. This asks blockstream.info and mempool.space for those blocks only; both must agree.

What the check found

Nothing checked yet.

What each level means

L1. The pack agrees with itself: Each fingerprint matches its contents, each file matches its fingerprint, and nothing the pack lists is missing.
L2. The record is linked to the timestamped fingerprint: Each fingerprint includes the one before it, so the company’s entries between the record and its timestamp show the link. Only a pack made with executive access holds them.
L3. The Bitcoin proof leads to a block: The .ots proof turns the fingerprint into the value one Bitcoin block must hold. Worked out on this computer.
L4. That Bitcoin block holds it: Needs that block’s header: a headers file, the online look-up, or your own Bitcoin node. Only then does the page say “External timestamp verified”.
L5. Made after a public beacon round: A record saved with a Cibotti time proof line names a public random number (a drand round) that nobody could know in advance. This page checks the number and its time, not its signature.

What no pack shows: that the company’s ledger holds nothing else (a pack shows only what is in it); that what a record says is true; when or where a photo was taken.