Question 60
A firm rotates encryption keys but leaves an old compromised key able to decrypt newly generated records. What change is needed for effective cryptographic separation?
Explanation
Correct Answer
Rotation must change which key protects future content, not merely relabel the original secret. Key custody, confidentiality and integrity are distinct requirements: a tool that encrypts bytes is not automatically a valid source of identity, trust or hardware-backed attestation. The case turns on leaves an old compromised key able to decrypt newly generated records; “Use a fresh active data-encryption key and prevent new data from using the compromised one” addresses that precise condition. “Publish the compromised key in an internal FAQ” is not equivalent because further distribution increases exposure instead of separating new ciphertext.
Incorrect Answers
Continued use perpetuates the same compromise path. Encryption addresses readability of protected data. Authentication, correct permissions and availability must still be enforced separately. In the reported situation, leaves an old compromised key able to decrypt newly generated records. The effective mechanism is “Use a fresh active data-encryption key and prevent new data from using the compromised one”: rotation must change which key protects future content, not merely relabel the original secret.
Further distribution increases exposure instead of separating new ciphertext. The evidence is leaves an old compromised key able to decrypt newly generated records. Cryptographic controls differ by function: encryption conceals information, signatures provide integrity and signer authentication, and key management governs the secrets and trust supporting both. By contrast, “Use a fresh active data-encryption key and prevent new data from using the compromised one” operates on the specific concern: rotation must change which key protects future content, not merely relabel the original secret.
Query wait settings do not restrict compromised-key decryptability. Cryptographic controls differ by function: encryption conceals information, signatures provide integrity and signer authentication, and key management governs the secrets and trust supporting both. Here the decisive fact is leaves an old compromised key able to decrypt newly generated records. “Use a fresh active data-encryption key and prevent new data from using the compromised one” matches that requirement because rotation must change which key protects future content, not merely relabel the original secret.






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