Bedregal, Benjamin René CallejasOliveira Filho, Isaac de Lima2014-12-172010-07-162014-12-172010-02-26OLIVEIRA FILHO, Isaac de Lima. Mestre em Sistemas e Computação. 2010. 117 f. Dissertação (Mestrado em Ciência da Computação) - Universidade Federal do Rio Grande do Norte, Natal, 2010.https://repositorio.ufrn.br/jspui/handle/123456789/18006In this work will applied the technique of Differential Cryptanalysis, introduced in 1990 by Biham and Shamir, on Papílio s cryptosystem, developed by Karla Ramos, to test and most importantly, to prove its relevance to other block ciphers such as DES, Blowfish and FEAL-N (X). This technique is based on the analysis of differences between plaintext and theirs respective ciphertext, in search of patterns that will assist in the discovery of the subkeys and consequently in the discovery of master key. These differences are obtained by XOR operations. Through this analysis, in addition to obtaining patterns of Pap´ılio, it search to obtain also the main characteristics and behavior of Papilio throughout theirs 16 rounds, identifying and replacing when necessary factors that can be improved in accordance with pre-established definitions of the same, thus providing greater security in the use of his algoritmapplication/pdfAcesso AbertoCriptoanáçiseCriptografiaAlgoritmoPapiliomasterThesisCNPQ::CIENCIAS EXATAS E DA TERRA::CIENCIA DA COMPUTACAO::SISTEMAS DE COMPUTACAO