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Audit trail

What is recorded, how integrity is checked, export.

Every action in a study is recorded: who, when, from which address, old and new value, reason. Records cannot be changed or deleted, not even directly in the database.

Integrity check

Each study's records are linked by a SHA-256 hash chain: every record carries the fingerprint of the previous one. If someone alters a record behind the system's back, the chain breaks. Every night the portal checks all chains from their first record and remembers how far each chain is intact. A failure shows on the Portal Owner's desk.

“Verify integrity” on the audit page checks that this last intact record is still there and unchanged, then every record added since the nightly check. So it answers in seconds even in a registry of millions of records. If very many records were added (over 100 000) or the chain was never checked in full, the check goes to a background job: you get an e-mail, and the result shows when you press the button again.

Checking the chain At night the whole chain is checked; the button checks only what was added since. Nightly check from the first record read in portions Checkpoint No. and hash of the last intact record “Verify” button checkpoint unchanged? + the new records Long tail checked in the background, e-mail If the chain is shorter than its checkpoint, the check reports a break: records missing from the end show too.

The database refuses to change, delete or empty (TRUNCATE) the audit trail. If someone does it behind the system's back all the same, the check shows the break. Records missing from the end of a chain show too: the chain then has fewer records than at the last check.

Export

“Download CSV” exports the study's audit trail for the archive or an inspection. It opens in Excel.

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