What security principle addresses the issue of "Security by Obscurity"?

Open Design is one of Saltzer and Schroeder's foundational security design principles, which explicitly states that the security of a system should not depend on the secrecy of its implementation or design. This directly addresses 'Security by Obscurity' by asserting that algorithms, mechanisms, and designs should withstand public scrutiny - only keys or credentials should be secret, not the overall design.

Segregation of Duties (SoD) is a control that divides critical tasks among multiple individuals to prevent fraud and error, and does not address reliance on secrecy of design as a security mechanism.

Role Based Access Control (RBAC) restricts system access based on a user's assigned role, which is an access management principle and has no direct relationship to countering security through obscurity.

Least Privilege limits users and processes to only the permissions necessary for their tasks, reducing attack surface, but does not specifically counter the concept of relying on hidden designs for security.