Non-repudiation

How it works

Logs show an event. A signed receipt binds a party. AS2 MDNs are the business version of that receipt. A read-tracking pixel is not non-repudiation.

A partner claims the 1 GB orders file never arrived. The MDN is signed and timed at 01:17. They stop arguing and look at their importer. Without the receipt, the argument stays open.

How it differs

Non-repudiation is not delivery of a link. A sent mail is not a receipt.

A log on only one side is weaker than a signed receipt both sides keep.

Store the receipt with the file hash.

On the ticket

• The practical close is a log line: time, actor, byte count, result.
• Without that line the transfer is a story.
• With it, the next person can see whether this door did what the ticket claimed.
• If the path is shared, say so in the partner profile so a later change does not silently pick a different limit, key, or region.
• On a real ticket, write down the door, the byte count, and the clock.
• For non repudiation, that means naming the host or bucket, the expected size, and the time the other side must have a complete file.
• A progress bar is not that record.
• A 200 response that arrives before the complete call is not that record.
• If a retry is allowed, say how many and whether it resumes.
• If a person must approve the send, name the person.
• Partners who receive non repudiation files should match on hash or size before they import.
• A same-length corrupt file passes a size check and fails a hash.
• Keep the published hash off the only channel an attacker can edit, or treat it as a corruption check rather than a substitution check.
• When the path changes, new key, new region, new cap, update the profile the same day so the next run does not use a stale limit.