Security is a process, not a product (No perfect security)Statement of what is and what is not allowedYou can design a policy depending on your needSecurity of the design and implementation of software and hardwareSecurity Policy NotionSecurity MechanismSecurity StateSecurity LevelSecurity Label www.cs.cmu.eduhttps://www.cs.cmu.edu/~rdriley/487/papers/Thompson_1984_ReflectionsonTrustingTrust.pdfcss.csail.mit.eduhttps://css.csail.mit.edu/6.858/2015/lec/lampson.pdf