Attacks of simple block ciphers via efficient heuristics

Recent years have witnessed a significantly increased interest in computer security. Efforts in the area of design of ciphers and their attacks have progressed at almost competing rates. Though brute force attack is successful for simple ciphers, cryptanalysis of complex ciphers warrants specialised techniques and powerful computing systems. Several heuristic techniques have assumed significance over the past few years, in the context of attacks of simple stages of certain ciphers. This paper presents a systematic study of efficient heuristics in the successful attacks of some block ciphers which though simple are representative ones in computer security parlance.