Problem Statement
Differentiate between encryption at rest and encryption in transit and state why both are needed.
Explanation
Encryption in transit protects data while it moves between systems (for example using TLS or VPNs). Encryption at rest protects data stored on disks or in databases from being read if the storage media is stolen or compromised. Both are needed because protecting only one phase leaves the other vulnerable: if you encrypt in transit but store plaintext data, a thief could access it easily. Conversely, encrypting at rest but moving data unprotected exposes it to interception. A full security posture covers both.
