Which term describes the principle of keeping data inaccessible to unauthorized users?

• A. Non-repudiation
• B. Integrity
• C. Availability
• D. Confidentiality

Answer: (D)

Confidentiality is the principle that keeps data inaccessible to unauthorized users. It relies on mechanisms like authentication, authorization, and encryption to ensure that sensitive information can only be viewed by those you approve. For example, password protections and access control lists restrict who can open a file, and encryption ensures that data remains unread if it’s intercepted or accessed without the proper keys. Other properties address different concerns: integrity focuses on preventing unauthorized changes to data, non-repudiation ensures the origin of a message can be proven, and availability guarantees data or systems are accessible when needed. So, keeping data secret from unauthorized parties is what confidentiality is all about.