In the cipher block chaining (CBC) mode of operation, the plaintext of the first block is XORed with the initialization vector (IV) and serves as the input of a block cipher. Which of the following best describes the purpose of the binary operation of plaintext and IV? (Wentz QOTD)
A. Confusion
B. Diffusion
C. Permutation
D. Substitution
Kindly be reminded that the suggested answer is for your reference only. It doesn’t matter whether you have the right or wrong answer. What really matters is your reasoning process and justifications.
My suggested answer is B. Diffusion.
Wentz’s book, The Effective CISSP: Security and Risk Management, helps CISSP and CISM aspirants build a solid conceptual security model. It is a tutorial for information security and a supplement to the official study guides for the CISSP and CISM exams and an informative reference for security professionals.
Reference
- Bitwise operation
- Block cipher mode of operation
- Confusion and diffusion
- Substitution–permutation network
在區塊型加解密器塊鏈接 (CBC) 操作模式中，第一個區塊的明文與初始向量(IV)進行XOR算，並作為區塊型加解密器的輸入。 以下哪項最能描述明文和 IV 作二元運算的目的？(Wentz QOTD)
A. 混淆 (Confusion)
B. 擴散 (Diffusion)
C. 排列 (Permutation)
D. 取代 (Substitution)