Question 1 [7 pts] Describe how a block cipher works by drawing a simple diagram showing all the components of the operation. Question 2 [7 pts] What is the codebook attack? Why this attack is feasible when 16 or 32-bit blocks have been used; but not feasible when 64-bit blocks have been used? Block Cipher Codebook Attack

Block Cipher Codebook Assault

A block cipher is a sort of symmetric encryption algorithm that operates on a fixed-size block of knowledge at a time, utilizing a secret key. It really works by dividing the plaintext message into blocks of a set dimension after which encrypting every block utilizing the key key (Sharma, 2018). The fundamental construction of a block cipher consists of the next parts: Plaintext: That is the message that must be encrypted. Key: That is the key code that’s used to encrypt and decrypt the message. Encryption algorithm: That is the mathematical operate that’s used to carry out the encryption and decryption. Ciphertext: That is the encrypted model of the plaintext message. To higher perceive how a block cipher works, let’s take into account the next easy diagram: Plaintext —> Encryption algorithm —> Ciphertext. However, a codebook assault is a sort of cryptanalytic assault that includes using a codebook, which is a precomputed desk of all doable plaintext/ciphertext pairs (Jha, 2018). This assault is possible when 16 or 32-bit blocks have been used as a result of the variety of doable plaintext/ciphertext pairs is comparatively small, making it simpler for the attacker to discover a match. Nevertheless, when 64-bit blocks are used, the variety of doable pairs turns into a lot bigger, making it infeasible for the attacker to discover a match utilizing this technique (Rouse, 2018). Cont…