Design and FPGA Implementation of the SCAN Encryption Algorithm

1 Acknowledgments I would like to acknowledge the guidance provided by my advisor, Prof. Dollas at every stage of work on this thesis. I also would like to thank Prof. D. Pneumatikatos and Prof. K. Kalaizakis for reviewing my thesis and participating in my thesis defense and the staff, the undergraduate and the postgraduate students of the Microprocessor and Hardware Laboratory. Introduction Encryption, the conversion of information into code, which is intelligible only for an authorized receiver, has intrigued men since ancient times. Historically, cryptographic techniques have been developed for diplomatic or military applications but today they can be found everywhere in private and public sectors where confidential information is crucial. The first system of military cryptography was the " skytale " , invented by the Spartans as early as the fifth century B.C [1]. The secret message was on the parchment down the length of the skytale. The parchment is then unwound and send on its way, where it can only be read if it is wrapped around a baton of the same thickness as the first. Cryptology, the science of code and cipher systems, start to develop not until the First World War. Until then few papers about cryptology have been published. The first notable paper about cryptography was Claude Shannon's paper " The Communication Theory of Secrecy Systems " , which appears in 1949 [2]. The revolution of telecommunication, which has produced a vast amount of transmitted confidential data, has initiated the flush of the cryptology. However, the science of cryptology differs from all the other sciences in a rather striking way: there is no public feedback about how cryptographic systems fail. Designers of cryptographic systems are at a disadvantage to most other engineers, in that information on how or if their systems fail is hard to get. The major users have traditionally been government agencies, which are very secretive about their mistakes. The National Security Agency (once called " No Such Agency ") spends thousands of millions dollars to cryptanalyze new algorithms and the publition of this achievement would meaning that this algorithm will stop being used. Cryptology also presents a difficulty not found in normal academic disciplines: the need for the proper interaction of cryptography and cryptanalysis. Exposing flaws in these designs is far harder than designing them in the 4 first place. The result is that the competitive process, which is one strong motivation …