CAS-002 · Question #870
A security solutions architect has argued consistently to implement the most secure method of encrypting corporate messages. The solution has been derided as not being cost effective by other…
The correct answer is A. One time pads. This question identifies the encryption scheme that uses symmetric keys, is theoretically unbreakable, but demands exceptional key management overhead that makes it cost-prohibitive.
Question
A security solutions architect has argued consistently to implement the most secure method of encrypting corporate messages. The solution has been derided as not being cost effective by other members of the IT department. The proposed solution uses symmetric keys to encrypt all messages and is very resistant to unauthorized decryption. The method also requires special handling and security for all key material that goes above and beyond most encryption systems. Which of the following is the solutions architect MOST likely trying to implement?
Options
- AOne time pads
- BPKI
- CQuantum cryptography
- DDigital rights management
How the community answered
(54 responses)- A78% (42)
- B2% (1)
- C6% (3)
- D15% (8)
Why each option
This question identifies the encryption scheme that uses symmetric keys, is theoretically unbreakable, but demands exceptional key management overhead that makes it cost-prohibitive.
One-time pads use a symmetric key that must be truly random, exactly as long as the plaintext, and never reused, making them information-theoretically secure - an attacker gains zero mathematical advantage even with unlimited computing power. The prohibitive cost derives from the requirement to securely generate, physically distribute, protect, and destroy key material in a volume equal to all data being encrypted, which is the special handling that far exceeds normal encryption systems.
PKI uses asymmetric encryption based on mathematically related public and private key pairs, not symmetric keys as specified in the question stem.
Quantum cryptography uses principles of quantum mechanics such as quantum key distribution (QKD) to detect eavesdropping - it is not a traditional symmetric key encryption system as described.
Digital rights management is a framework for enforcing access and usage policies on digital content, not a standalone cryptographic algorithm or encryption method with the properties described in the question.
Concept tested: One-time pad properties - symmetric key, perfect secrecy, key management cost
Source: https://csrc.nist.gov/glossary/term/one_time_pad
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