Each register entry is linked to the one before it using a cryptographic hash chain. If any past record is edited or deleted, the chain breaks — and that break is detectable.
The integrity badge
At the top of the Controlled Drug Register you will see an integrity badge. A green Register Verified badge means the full chain is intact. A red Integrity Failed badge means a record has been altered and should be investigated.
This gives you tamper-evidence: you can demonstrate to an inspector that your records are complete and unchanged.