Which of the following measures is MOST effective against insider threats to confidential information?

Role-based access control (RBAC) is the most effective measure against insider threats to confidential information because it restricts access to sensitive data based on the roles assigned to individuals within an organization. By ensuring that employees can only access the information necessary for their specific job functions, RBAC minimizes the risk of unauthorized data exposure or misuse. This principle of least privilege is critical in mitigating potential insider threats, as it limits the number of users who have access to confidential information, thereby reducing the opportunities for malicious intent or accidental breaches.

Moreover, RBAC can adapt to organizational changes, ensuring that employees receive the appropriate access rights as they transition between roles or when their job requirements change. This can help organizations maintain tighter control over confidential information, making it a cornerstone for protecting sensitive data against insider threats.

While other measures, such as audit trail monitoring and implementing a privacy policy, can enhance overall security and help detect or mitigate breaches, they do not directly restrict access to sensitive data in the way that RBAC does. Defense in depth is a strategy for layered security controls but may not specifically address the unique challenges posed by insider threats effectively.