What is the process of full disk encryption primarily concerned with?

Full disk encryption is primarily concerned with protecting all data stored on a physical drive by encrypting it in its entirety. This means that when data is written to the disk, it is automatically encrypted, and when it is read from the disk, it is decrypted in real-time for use. This process ensures that unauthorized users cannot access the sensitive information on the disk if they gain physical possession of it, as the data remains secure even when the system is powered down.

The focus on real-time decryption is critical because it allows users to interact with their files seamlessly without needing to manually decrypt each file. The encryption operates transparently in the background, ensuring robust security while maintaining usability for the legitimate user.

In contrast, the other options relate to different aspects of data security. Encrypting files during transit pertains to securing data as it moves across networks, which does not involve the entire disk. Storing files with no encryption represents a lack of security measures altogether, and encrypting communication between servers targets a specific area of data transmission security rather than protecting the entire disk's content. Therefore, the essence of full disk encryption lies in its ability to safeguard data at rest by ensuring that decryption happens seamlessly and transparently when the data is accessed.