Date Added: Mar 2010
Cryptography, which is considered as a science of present century is actually an ancient technique. Since early civilizations, different methods have been developed to send secret messages. But with advent of Internet, data privacy face more risks, thus need of information security increases which leads to the new developments of cryptography. In classic cryptography, mainly two techniques are used: SUBSTITUTION and PERMUTATION. And the fact is that Modern cryptography is mainly based on these two very basic techniques. This paper analyze the strength or security of Substitution and Permutation techniques from Cryptanalysis perspective.