DCrypt: An Automatic Cryptanalysis tool for Secret Key Ciphers (T-0665) (MFN 2845)

Abstract

This report revolves around the classical encryption methods which were once thought to be unbreakable. In particular it deals with three of these ciphers, which are; Caesar’s cipher, Mono-alphabetic substitution cipher & Vigenere cipher. It discusses the techniques these encryption methods employ to encipher/decipher messages. The aim of this is to highlight the weaknesses of these ciphers and to come up with an implementation that would be able to break them automatically. The outcome of the project is a fully operational system that uses the methods discussed in the report to break the classical encryption ciphers. The results are promising and prove that these ciphers can also be broken without using statistical analysis. Though the system does not use statistical analysis to break the Caesar & mono-alphabetic cipher, it is obvious that it could benefit from using these techniques to produce a more robust application. Hence a possible extension to the system would be to include these techniques to form a hybrid solution