How signed writing receipts work

A ByHuman receipt is a cryptographically signed record of an observed writing session. It gives readers evidence about the process behind a piece of text. It is not an AI detector and it does not identify the author by itself.

What ByHuman observes

While a person writes in the ByHuman editor or a supported composer, the software records process events such as typing, pasting, deleting, and pauses. The resulting receipt summarizes the session and commits to the event log without publishing every private intermediate draft.

• typed and pasted character counts;
• edits, deletions, and session timing;
• a hash that binds the receipt to its event log;
• the final text hash and receipt version.

How a receipt is created

1. The editor records the writing events in order.
2. The same canonical receipt logic summarizes the session.
3. ByHuman signs the receipt with an Ed25519 private key.
4. The public proof page exposes the receipt and signature.

The same canonicalization and receipt logic is used when the receipt is created and when a third party checks it. This keeps the signed payload consistent across the editor, signing service, and verifier.

How verification works

A verifier reconstructs the canonical receipt payload, checks the event-log hash, and verifies the Ed25519 signature against ByHuman's published public key. A valid signature shows that the signed receipt has not been changed since it was issued.

What the evidence does and does not show

It can show

• that a specific writing process was observed;
• how much text was typed, pasted, edited, and deleted;
• that the signed receipt has not been altered.

It cannot show

• who was physically at the keyboard;
• whether an idea originated with a person or a tool;
• that every fact in the finished text is accurate;
• that text is “100% human-written.”

The useful claim is narrow: verified writing process. Readers still decide how much that process evidence matters in context.