What is the difference between encryption at rest and encryption in transit?

• A. In transit encrypts stored data.
• B. At rest protects data moving across networks.
• C. At rest protects stored data.
• D. In transit protects data moving across networks.

Answer: (D)

The main idea is to distinguish when data is protected: during transmission versus while stored. Encryption in transit protects data as it moves across networks, preventing others from reading or tampering with it while it travels between systems (for example, TLS/SSL securing HTTPS traffic, or IPsec VPNs). Encryption at rest, on the other hand, protects data that is stored on disks, databases, or backups, so that if the storage medium is accessed or stolen, the data remains unreadable. So the correct statement is that encryption in transit protects data moving across networks.