" Data Communication Ciphering Systems " Analysis of Block Cipher Systems

Abstract

Communication Systems are vulnerable to passive wiretapping (Eavesdropping) which threats secrecy and active wiretapping (Tampering) which threats authenticity. This thesis is devoted to study and analyze Block Cipher techniques applied in Data Communication Ciphering Systems. Early Cipher Systems including Substitution and Transposition Ciphers are presented. Modem Cipher Systems including Stream Cipher Systems, Block Cipher Systems and Public Key Cryptosystems are studied. Block Cipher Systems are studied and analyzed. A Complete package of different elements which affect the security level of Block cipher Systems is presented in this thesis. A Complete package of the significant statistical tests for local Randomness is presented in this thesis including mathematical description.