Security Architecture & Engineering

Subjects are granted only the minimum rights/permissions necessary to perform their job, and no more.

Layering multiple, diverse security controls so that if one fails, others still protect the asset.

Systems ship hardened with the most secure configuration; access is denied unless explicitly allowed.

Fail-open (fail-safe) permits access when a control fails, prioritizing availability; fail-closed (fail-secure) denies access, prioritizing security/confidentiality.

Dividing a critical task among multiple people so no single individual can complete it alone, reducing fraud risk.

Dual control requires two people to act simultaneously to complete one action (e.g., two keys); SoD splits steps of a process across people.