An organization is developing a new, highly sensitive application. During the design phase, the security architect proposes implementing a Trusted Computing Base (TCB) for critical security functions. What is the primary advantage of designing a TCB for this application?
- AIt simplifies the application code by offloading all security functions to the operating system.
- BIt reduces the attack surface by confining security-critical operations to a smaller, isolated component.
- CIt ensures that the entire application is provably secure and free from vulnerabilities.
- DIt automatically generates security policies based on application requirements.
Show answer & explanationAnswer & explanation
Correct answer: B. It reduces the attack surface by confining security-critical operations to a smaller, isolated component.
The primary advantage of a TCB is to limit the amount of code and components that are absolutely critical for enforcing the security policy. By confining security-critical operations to a smaller, well-defined, and isolated component, the TCB reduces the attack surface and makes it more feasible to rigorously verify its correctness, thereby enhancing overall system security.
Why the other options are wrong
- A. A TCB defines what components are trusted, not necessarily offloading all security functions, and its goal is not simplification but rigorous security.
- C. While a TCB aims for high assurance, it does not guarantee the 'entire application is provably secure and free from vulnerabilities'; it focuses on the trusted portion.
- D. A TCB is a set of components that enforce security; it does not automatically generate security policies.
Trusted Computing Base (TCB)
The set of all protection mechanisms within a computer system (hardware, firmware, software) that are responsible for enforcing the security policy. It must be trustworthy and correct.
- Enforces security policy
- Smallest possible set of components
- Its correctness is paramount for system security
Memory trick: TCB: Tiny Core, Big Security. Less trusted code, more reliability.