Tony wants to integrate a 128-bit symmetric block cipher with key sizes of 128, 192,...

In CEH v13 Module 14: Cryptography, Serpent is detailed as one of the finalists in the Advanced Encryption Standard (AES) competition, known for its strong security characteristics.

Key Features of Serpent:

128-bit block size, and key sizes of 128, 192, or 256 bits.

Uses 32 rounds of substitution and permutation.

Operates on four 32-bit words per block.

Employs 8 different S-boxes, each with a 4-bit input and 4-bit output.

Designed to provide high security and resistance against differential cryptanalysis.

Option Clarification:

A. TEA: Uses a Feistel structure with simple operations, but not 32 rounds with S-boxes.

B. CAST-128: Has 64-bit block size and fewer rounds.

C. RC5: Variable block and key sizes but doesn’t use 32 rounds with fixed S-box design.

D. Serpent: Matches all given features.