Why It Matters
Security logging and monitoring is what lets you notice an attack in progress and reconstruct what happened afterward. Without it, breaches go undetected for long periods and incident response is guesswork. It is one of the most commonly neglected controls.
What To Log
- Authentication events including logins, failures, and password changes.
- Authorization decisions, especially denials and access to sensitive resources.
- Administrative actions and configuration changes.
- Each entry should carry who, what, when, and where, with a correlation id.
Doing It Safely And Usefully
- Never log secrets such as passwords, tokens, or full card numbers.
- Ship logs to a central, tamper resistant store so an attacker cannot erase them.
- Define alerts for high signal events and review them, since logs no one watches help no one.
- Retain logs long enough to support investigation.
Key idea
Log the security relevant events with full context, centralize them safely, and alert on them, because detection and investigation depend on logs you actually watch.