Which security principle advocates for a design that minimizes shared functions among different users?

• A. Least Astonishment
• B. Least Common Mechanism
• C. Economy of Mechanism
• D. Modularity

Answer: (B)

The principle that advocates for a design minimizing shared functions among different users is the Least Common Mechanism. This principle emphasizes the importance of reducing the dependencies and common resources that multiple users or components share. By doing so, it decreases the potential attack surface, limiting the opportunity for one user to inadvertently or maliciously affect another user's operations or data. This approach promotes a more secure environment by ensuring that each user operates independently, thus isolating their functions and protecting their data from unintended access or interference.

The rationale behind this principle revolves around creating a more controlled access environment where shared mechanisms could be exploited. By minimizing overlap, security is enhanced, as it limits the chances of unauthorized access and potential vulnerabilities associated with shared resources.