Verification answers one question: is this record genuine? It replays every recorded edit, re-derives the finished document byte for byte, and re-checks every link in the chain. If anything was altered, removed, reordered or backdated after the fact, verification fails loudly and points at the break.
What each line of the panel means
- Hash chain. Every edit is hashed together with the hash of the edit before it, so the whole history is one linked chain. A pass means no edit was changed, inserted, removed or reordered since it was recorded.
- Typing policy. The recorded edits obey the sealed editor’s rules: text arrived in human-scale keystrokes, not in machine-sized blocks.
- Document match. Replaying every edit from the empty page rebuilds exactly the document that was handed in, byte for byte. The submission is its own history, verified.
- Server countersignature: the checkpoints. While the student wrote, the editor periodically sent its current chain head to our server, which signed it against server time. Those checkpoints are the anchor: the student’s device can’t mint them, so a session can’t be fabricated or backdated later, even by someone with full control of their own computer. “Chain tip anchored to server time” means the ladder of checkpoints holds.
- Blocked attempts. How many times the editor refused something, usually pasted text. Context for a conversation, not a verdict; see why paste is blocked.
- Document SHA-256. The fingerprint of the final document. Anyone holding an exported copy can recompute it and confirm they’re looking at the same bytes.
What the seal means, and what it doesn’t
A passing in-product check establishes that the submitted document matches the writing record captured by Loam and that the chain and server checkpoints pass Loam’s checks. It is evidence of the captured writing process, not a detector score or a claim about the quality and truth of the ideas.
It does not prove who was at the keyboard, and it does not prove the words weren’t being read off a second screen. We say this plainly because tools that overclaim are how teachers end up defending scores they can’t explain. The seal makes the record trustworthy; the replay and your knowledge of the student do the rest.
Verifying a portable PDF
The public verifier previewis being built for author-issued Loam PDFs. It will read the file locally in the recipient’s browser, without sending the PDF to Loam, and show only the evidence level embedded by the author. The new format will use an asymmetric export seal so a public key can establish the Loam issuer and document binding offline.