Least Privilege and Complete Mediation

These two principles work together: least privilege limits what an entity can do, and complete mediation ensures that every access attempt is checked against those limits.

Least Privilege

Principle: Individuals and entities should only be given sufficient access and permissions to complete their assigned duties, no more.

Key Aspects

• Least privilege by default: Start with zero access and grant permissions incrementally as justified
• Minimal access permissions: Limit scope to reduce impact of fraud, compromise, or user error
• Reduced attack surface: Fewer permissions mean fewer opportunities for exploitation
• User accountability: When permissions are specific and narrow, audit trails are meaningful and anomalous activity is detectable

Application