Simplicity and Isolation

This skill combines two complementary design principles: economy of mechanism (minimize the number of components and code paths that enforce security) and least common mechanism (minimize sharing between components).

Economy of Mechanism

Principle: Designs should be simple, comprehensive, and should implement protection mechanisms so that unintended access paths do not exist.

The more complex something is, the harder it is to understand. If you cannot understand a system, you cannot identify and mitigate all its risks.

Key Aspects

• Simplicity: A simpler design is easier to understand, analyze, audit, and maintain. Complexity introduces opportunities for vulnerabilities.
• Minimize moving parts: Fewer components mean a reduced attack surface and fewer unexpected interactions
• Ease of understanding: Security mechanisms must be understandable to be implemented without introducing gaps and configured without misuse
• Avoid unnecessary features: Every feature increases the potential for exploitation. Include only what is essential.
• Maintainability: A clean, simple design allows seamless security updates without introducing regressions

Application