Which statement best describes encryption at rest versus encryption in transit?

• A. Both protect confidentiality; at rest protects stored data, in transit protects data moving across networks
• B. Encryption at rest protects stored data; encryption in transit protects data moving over networks
• C. Encryption at rest protects data in memory
• D. Encryption in transit encrypts files on disk

Answer: (B)

Data security depends on the state of the data. Encryption at rest applies to data that is stored on disks, databases, backups, or other storage media, protecting it if someone gains access to the storage itself. Encryption in transit protects data as it moves over networks, safeguarding it from eavesdroppers and tampering during transmission. The statement that best captures the distinction is that encryption at rest protects stored data, while encryption in transit protects data moving over networks. This makes the specific roles clear: one shields data at rest, the other shields data in transit. The other option is true in a general sense but adds a broader claim about confidentiality that doesn’t emphasize where each protection applies.