What is a Trusted System in Operating System?

Software is trusted software if we know that the code has been rigorously developed and analyzed, giving us reason to trust that the code does what it is expected to do and nothing more.

An operating system that manages data to make sure that it cannot be altered, moved, or viewed except by entities having appropriate and authorized access rights.

An operating system in which there exists a level of confidence (based on rigorous analysis and testing) that the security principals and mechanisms (e.g., separation, isolation, least privilege, discretionary and non-discretionary access control, trusted path, authentication, and security policy enforcement) are correctly implemented and operate as intended even in the presence of adversarial activity.

Certain key characteristics of Trusted Operating System

  1. Functional correctness.
  2. Enforcement of integrity.
  3. Limited privilege:
  4. Appropriate confidence level

Security professionals prefer to speak of trusted instead of secure operating systems.

  • Secure reflects a dichotomy: Something is either secure or not secure.
  • Trust is not a dichotomy; degrees of trust