Amazon.com description: Product Description: DES, the Data Encryption Standard, is one of several cryptographic standards. The authors of this text detail their cryptanalytic "attack" upon DES and several other systems, using creative and novel tactics to demonstrate how they broke DES up into 16 rounds of coding. The methodology used offers valuable insights to cryptographers and cryptanalysts alike in creating new encryption standards, strengthening current ones, and exploring new ways to test important data protection schemes. This book introduces a new cryptographic method, called differential cryptanalysis, which can be applied to analyze cryptosystems. It describes the cryptanalysis of DES, deals with the influence of its building blocks on security, and analyzes modified variants. The differential cryptanalysis of "Feal" and several other cryptosystems is also described. This method can also be used to cryptanalyze hash functions, as is exemplified by the cryptanalysis of "Snefru".