What does the principle of least common mechanism imply in security design?

• A. minimize shared functions among users
• B. maximize shared access to resources
• C. reduce the number of security measures
• D. standardize all operational procedures

Answer: (A)

The principle of least common mechanism in security design emphasizes minimizing the shared functions and resources among users to reduce the risk of accidental or malicious breaches of security. By limiting the mechanisms that are accessible to multiple users, organizations can manage privileges more tightly and ensure that only those who truly need access to particular functions or data receive it. This minimizes potential points of attack, effectively decreasing the probability of a security compromise resulting from shared access. In practice, implementing this principle means creating isolated environments for different user roles and functions, thereby enhancing overall security posture by reducing the potential cross-contamination of security vulnerabilities.

The other choices reflect concepts that do not align with the principle of least common mechanism. Maximizing shared access to resources contradicts the idea of limiting exposure to risk. Reducing the number of security measures might appear beneficial, but it can compromise overall security if important protections are removed. Standardizing all operational procedures could lead to unnecessary overlap in functions and access, which again runs counter to the idea of minimizing shared mechanisms.