What does the term "Implicit Deny" refer to in access control?

The term "Implicit Deny" in access control refers to the principle that access is restricted unless a specific permission has been explicitly granted. This means that if there are no permissions configured for a user, group, or role to access a resource, they will automatically be denied access to that resource.

This approach ensures a high level of security by default; it assumes that all resources are off-limits until an administrator determines that a user should have access. By requiring explicit permission for each user or role, organizations can better control who can access critical data or systems, thereby reducing the risk of unauthorized access and potential data breaches.

The other options do not align with this principle. For instance, allowing access by default contradicts the idea of implicit denial, as would granting access based on roles without strict permission checks. Logging failed access attempts is a monitoring function but does not pertain directly to the access control philosophy encapsulated by the term "Implicit Deny."