Data Encryption Standard - DESDES was developed as a standard for communications and data protection by an IBM research team, in response to a public request for proposals by the NBS - the National Bureau of Standards (which is now known as NIST). By: T.N.Srimanyu (12MCMB06) Ritika Singla (12MCMB15) M.Tech(IT)
DES - Basics DES uses the two basic techniques of cryptography - confusion and diffusion. At the simplest level, diffusion is achieved through numerous permutations and confusion is achieved through the XOR operation.
DES - The 16 Rounds The basic process in enciphering a 64-bit data block and a 56-bit key using the DES consists of: • An initial permutation (IP) • 16 rounds of a complex key dependent calculation f • A final permutation, being the inverse of IP
IMPROVED DES ALGORITHM BASED ON IRRATIONAL NUMBERSIEEE Int. Conference Neural Networks & Signal ProcessingZhenjiang, China, June 8~10, 2008
Irrational Numbers Irrational numbers, which are similar to datasequences generated form chaotic system, are infinite and non-cyclic.Therefore using irrational numbers to encrypt will provide higher security without strict chaos synchronization.
Advantages The improved scheme prevents the key from being directly involved in the production of sub-keys.It can increase the randomness of the production of the sub-keys and use different sub-keys each group.The key space is extended.
ConclusionThis paper designs an encryption algorithm with better security, bigger secret-key space and higher encrypting efficiency.This scheme can expand the key space without any more running time and enhance the security of the encryption algorithm.The algorithm has wider foreground applications based on these advantages.