A regular activity log is only as trustworthy as the person with database access. I built one that even I cannot quietly change, because the database itself refuses. Here is how.

Six parts, and the trust comes from math and rules, not a promise.

1. Insert only. The log accepts new rows but nothing else. There is no edit and no delete.
2. The database enforces it. Two database triggers hard-reject any attempt to update or delete a row, so the rule holds even against someone with direct access.
3. Chain the rows. Each new row includes a hash of the one before it, so the whole log is a chain. Change any row and the chain breaks, visibly.
4. Log every change automatically. Every meaningful action writes a row on its own, so nobody has to remember to log.
5. Record the diff. Each entry stores exactly what changed, not just that something did.
6. Provable, not promised. You can prove the log is intact by checking the chain, instead of trusting that nobody touched it.

Any business that needs a trustworthy record, compliance, finance, anything audited, wants this floor. Trust by math, not by policy. The chain above is the whole design, and the math does the trusting.

From a compliance-grade asset platform. Everything described here is something I actually run; nothing on this bench is theoretical.