Can an audit log be edited without anyone knowing?

Yes, if it is an ordinary log. A log kept in a file or database that the organisation controls can be changed or have entries deleted by anyone with enough access, and nothing outside the organisation records what it said before. You can see this for yourself with the free Editable Log Test at sebbi.pro: load any log in your browser, change or delete one line, and the test shows that the file still opens normally and carries no mark of the edit. It then shows the same edit caught to the exact line by a fingerprint chain, and lets you timestamp the true fingerprint in Bitcoin free, so that from that moment any edit is provable by anyone. Nothing is uploaded: the log stays in your browser and only the 64-character fingerprint is sent if you choose.

How it works

1. Open https://sebbi.pro/log-test and paste a log or choose a file.
2. Tap a line and change or delete it.
3. Read the verdict: self-attested or independently checkable.
4. Tap to timestamp the true fingerprint in Bitcoin, free.
5. To protect every future record, seal each one as it is written with pip install sebbi or npm install sebbi.