A subject in cybersecurity is an active entity that initiates actions and requests access to resources. Among the options provided, auseris the correct example of a subject because users actively authenticate, request access, and perform operations on systems.
Files and filenames are objects, not subjects. They are passive entities that store data and do not initiate actions. A fence is a physical security control and does not function as a subject within access control models.
Subjects can include human users, system processes, applications, or services acting on behalf of users. In access control decisions, systems evaluate whether a subject is authorized to perform a specific action on an object based on identity, role, or security label.
Understanding the distinction between subjects and objects is essential for designing secure systems and implementing access control policies. It supports core principles such as least privilege and separation of duties. Without clearly identifying subjects, organizations cannot accurately enforce permissions, monitor activity, or perform effective auditing and incident response.
