How do you approach the challenge of data encryption both at rest and in transit?

Example Answer

I would start with the threat model and data flow: which stores and connections carry sensitive data, which administrators or services can decrypt it, and what an attacker could obtain from a stolen disk, database account or application host. Encryption at one layer does not remove access through an authorized decryption path.

For application-level encryption at rest, I would use a maintained library and an authenticated encryption construction, such as AES-GCM where appropriate. Naming AES and a key length alone does not specify integrity protection. The implementation must meet nonce requirements and reject failed authentication before using plaintext. For managed database or storage encryption, I would verify the service's actual protection boundary and key-management options rather than inventing a custom format.

For data in transit, I would use a supported TLS configuration with certificate and hostname verification, including internal service paths. Disabling verification to fix a connection error defeats endpoint authentication. I would document where TLS terminates and whether the next hop remains protected.

Keys need restricted use permissions, separation from encrypted data, an inventory, rotation and recovery procedures, and an incident response plan. A managed key service or HSM can help, but permissions and operational procedures still determine who can decrypt data. Rotation must preserve access to data encrypted under earlier keys until it is appropriately migrated or retired.

Verification

Test allowed and denied decrypt operations, certificate failures, corrupted ciphertext, rotation with existing data, recovery, and the loss or revocation of key access. Measure latency and service failure behavior alongside security checks. The absence of reported incidents is not proof that key management is correct. Use real experience when describing past results; this answer is a proposed approach.

Source

OWASP Cryptographic Storage, Transport Layer Security, and Key Management.