CriptoanÃlise Diferencial
AUTOR(ES)
Raimundo CorrÃa de Oliveira
DATA DE PUBLICAÇÃO
2003
RESUMO
Since the creation of the standard of encryption of data DES (Data Encryption Standard) in 1978, iterative ciphers of based private key in nets of Feistel have been constructed, aiming at to increase the security of the information stored and transmitted in unsafe environments of communications. Such ciphers, besides in general presenting one high level of resistance the criptoanalÃticos attacks, allow to efficient implementations in different platforms, being therefore a very attractive alternative for the protection of great masses of data. One of the techniques most efficient to criptoanalisar this type of cipher is the call Differential Cryptoanalysis, introduced in 1990 by Biham and Shamir. This work has as objective to present a study of the technique of Differential Cryptoanalysis, as well as demonstrating an application of the same one in the cryptoanalysis of the crypto-system of private key Blowfish, introduced for Schneier in 1994. Initially the work approaches the main related mathematical aspects with the cryptography of private key and, after that, presents an introduction to the area of Data locking, discoursing on important aspects of the same one, such as cryptography of private key and public key. Moreover, the crypto-systems of private key DES, RC5, IDEA and Blowfish are also described. The technique of the Differential Cryptoanalysis then is considered in details, where the most important concepts of the same one are examined, such as slight knowledge of the differential and characteristic pairs, among others. An application of the technique then is presented, in the evaluation of the degree of security of the block cipher Blowfish
ASSUNTO(S)
idea des criptoanÃlise diferencial blowfish rc5 seguranÃa de dados engenharia eletrica
