What is Append-only audit log?
An append-only audit log is a chronological record of security-relevant and administrative actions in a system, such as sign-ins, permission changes, data exports and deletions. New entries can be added, but existing entries cannot be edited or deleted through normal operations. This makes the log a reliable record for investigations, audits and regulatory evidence.
How Personal Academy handles it
Personal Academy keeps an append-only audit log: the database refuses edits and deletions of entries, and entries are kept for at least 365 days.
A worked example
Suppose a 300-person healthcare training provider is asked by an auditor who changed a learner completion record last quarter. The administrator searches the audit log for that learner and finds the entry: which administrator changed it, when, and what the old and new values were. Because the database refuses changes to log entries, the auditor can rely on the record as it stands.
Most systems keep some kind of log, but an ordinary log stored in a normal table or file can be altered by anyone with enough access. That undermines its value exactly when it matters, during an investigation of misuse by a privileged user. An append-only log removes that weakness by making entries immutable once written.
A useful audit entry records who acted (the user or service), what they did (the action and the object affected), when (a reliable timestamp), where from (for example the IP address or session) and, for changes, the values before and after. It should be written by trusted server-side code, not by the browser.
Immutability can be enforced in several ways. In a database, triggers or permissions can refuse UPDATE and DELETE on the log table for every role used by the application. Write-once storage and log shipping to a separate system add further protection. Some systems go further and chain each entry to the previous one with a cryptographic hash so that any tampering can be detected; append-only enforcement and hash chaining are separate properties.
Retention needs a policy. Regulations and customer contracts often require logs to be kept for a minimum period, while privacy law requires personal data not to be kept longer than necessary. A typical design keeps entries for a fixed minimum and then removes them through a controlled retention process, not by ad hoc deletion.
Audit logs support security monitoring, incident response, regulatory audits and customer questionnaires. They are only useful if administrators can search and export them, so review tools matter as much as storage.