A company's internal messaging system is being redesigned. The authentication procedures were so cumbersome that employees were using personal email to communicate. What is the security principle implemented in this scenario?

Fail-safe mechanisms are designed to prevent system failure by automatically switching to a safe state in the event of a malfunction. While important, this principle focuses on system design for reliability and does not address user behavior or the complexity of authentication procedures affecting employee compliance.

The zero-trust model operates on the premise that no user or device should be trusted by default, requiring continuous verification. Although this model aims to enhance security, the scenario highlights issues with user compliance due to cumbersome procedures rather than a lack of trust in users or devices.

The least common mechanism principle suggests that shared mechanisms should be minimized to reduce security risks. However, this principle does not directly relate to the usability issues faced by employees in the scenario; rather, it focuses on system design to limit potential vulnerabilities arising from shared resources.