Question

Given the following:

1) Plaintext: 93D₁₆
2) Initialization Vector: E₁₆
3) Simple Cipher: Rotate left 3 bits and invert result
4) Blocksize: 4
What is the CBC ciphertext in hexadecimal?
a) 4 4 7
b) 7 4 3
c) 4 4 3
d) 7 4 3

Answer 1

The CBC ciphertext in hexadecimal is '7 4 3' (option d).

Step-by-step explanation:

The question is asking for the Channel Block Chaining (CBC) ciphertext in hexadecimal. This encryption mode is commonly used in symmetric key cryptography. In this case, the plaintext '93D₁₆' is encrypted using the given initialization vector 'E₁₆' and the simple cipher 'Rotate left 3 bits and invert result'.

For CBC mode, each block of plaintext is XORed with the previous block of ciphertext before being encrypted. The first block is XORed with the initialization vector. The encrypted block is then used as the input for the next block.

So the CBC ciphertext in hexadecimal is '7 4 3' (option d).