- Economy of mechanism: Keep the design as simple and small as possible.
- Fail-safe defaults: Base access decisions on permission rather than exclusion.
- Complete mediation: Every access to every object must be checked for authority.
- Open design: The design should not be secret, but rather depend on the possession of keys or passwords.
- Separation of privilege: Where feasible, a protection mechanism should require two keys to unlock, rather than one.
- Least privilege: Every program and every user of the system should operate using the least set of privileges necessary to complete the job.
- Least common mechanism: Minimize mechanisms (or shared variables) common to more than one user and depended on by all users.
- Psychological acceptability: It is essential that the human interface be designed for ease of use, so that users routinely and automatically apply the protection mechanisms correctly.
Whitman, Michael E. “Principles of Information Security“