Certified Information Systems Security Professional (CISSP) Practice Exam 2026 – All-in-One Guide to Mastering Your Certification!

The statement that it encrypts the entire contents of a storage device accurately describes the functionality of Full Disk Encryption (FDE). FDE provides a comprehensive security measure by applying encryption to every bit of data that resides on a storage device, including system files, applications, and user data. This approach ensures that all data is secured at rest, meaning that if the device is lost or stolen, accessing the data without the proper credentials becomes exceedingly difficult.

FDE typically operates transparently to the user, meaning that once the device is unlocked with the correct authentication, it functions as usual without needing additional user actions to encrypt or decrypt data. This seamless integration is essential for maintaining usability while enforcing security.

Other options do not accurately reflect FDE's primary purpose. While there are methods for selective encryption based on permissions, that is characteristic of more granular encryption solutions, not full disk encryption. Additionally, FDE does not specifically focus on data in transit, which is a concern addressed by other encryption methods such as transport-level encryption. Lastly, FDE does not inherently improve data access speeds; in fact, it may slightly affect performance due to the overhead of encryption and decryption processes, although advancements in technology have minimized this impact.