Data at rest encryption focuses on protecting data when it is which?

• A. In transit
• B. Stored on disk or other media
• C. In memory
• D. During computation

Answer: (B)

Data at rest encryption secures data while it is stored on physical media. It protects information kept on disks, SSDs, tapes, or cloud storage from being read if the storage is stolen or accessed by someone without authorization. This is different from data in transit, which is data moving across networks, and data in use (in memory or during computation), which is being actively processed by a system. With data at rest, the information remains encrypted on disk and only decrypts when accessed by authorized applications or users with the proper keys, such as through full-disk encryption or database/file-level encryption. This helps ensure confidentiality even when storage media fall into the wrong hands.