Hardware Security
What can happen if poor-quality, predictable random numbers are used to generate cryptographic keys?
- AEncryption becomes faster
- BCiphertexts become twice as long
- CEven with a strong algorithm, the key can be guessed and the encryption broken
Show answer and explanation
Answer: C. Even with a strong algorithm, the key can be guessed and the encryption broken
Cryptographic security relies on attackers not knowing the key. If the random numbers used to make keys are biased, or not enough unpredictability has accumulated right after power-on, the space of possible keys shrinks and brute force can find them. Real cases have been reported in which flawed randomness left many devices with similar keys. Random number generation is one of the most fundamental building blocks of security.
- A. It has nothing to do with speed.
- B. It has nothing to do with length.
- C. Correct. Key unpredictability is the foundation of security.