Security Architecture System Principles

• Least Privilege
  • An entity (person or software) should have the least privilege necessary to carry out their responsibilities for the minimum time necessary.
• Privilege separation
  • High privilege operations are removed from components which are interacted with by external entities (person or software) and assigned to a separate higher assurance component
• Fail safe defaults
  • Systems should depend on secure defaults in the event of failure should deny access.
• Complete mediation
  • All accesses to a resource should be checked to ensure they are allowed.
• Separation of privilege
  • Access to a resource should not be granted on the basis of a single condition
• Least common mechanism
  • Mechanism used to access resources should not be shared
• Minimise attack surface
  • Minimise the system functions, interfaces, channels, methods and data which could be accessible to a malicious actor
• Limit trust
  • Minimise the elements that need to be trusted, including system components, client software, actual users and other systems.