Which of the following is an example of data encryption at rest?

• A. Disk Encryption
• B. TLS Encryption
• C. VPN Encryption
• D. End-To-End Messaging Encryption

Answer: (A)

Data encryption at rest protects information while it is stored, not while it’s moving over a network. Disk encryption applies cryptographic protection directly to the storage medium, so the data on the disk remains unreadable without the proper keys even if the drive is stolen or accessed by someone without authorization. This is the classic example of encryption at rest because the data is secured while it sits on disk.

In contrast, the other options focus on protecting data as it travels across networks. TLS encrypts the path between client and server, which is data in transit. A VPN encrypts traffic as it moves through a tunnel across networks, also in transit. End-to-end messaging encryption protects message content from sender to recipient, primarily addressing confidentiality during transit and at endpoints rather than the storage medium itself.