Comparative Randomness Analysis of DES Variants

Abstract

Background: Over the past few years, researchers have devoted efforts to enhance the robustness and randomness of the original DES cipher. These enhancements focused on improving multiple perspectives of the algorithm to deliver robust DES variants against typical attacks. Method: Recent publications and patent databases have been reviewed to investigate the potential enhancements in DES cipher algorithm. The enhancements have targeted the main components of DES including the F-function, S-boxes arrangements, and the key length. Result: This paper introduces a DES variant named Hashed Data Encryption Standard (HDES). The main idea behind HDES cryptographic algorithm is to provide a trade-off between fast encryption while ensuring a degree of randomness in the encrypted data. HDES employs several techniques including the use of a hash function and secure arrangements of S-boxes. The idea of using the hash is to create a fingerprint of the plaintext. This fingerprint is used to generate a seed and the subsequent round seeds. Conclusion: The randomness analysis of HDES and its counterparts DES and DESX have shown performance merits of HDES in terms of entropy difference, cipher data randomness, symmetric distance and encryption time. Keywords: Encryption algorithm, randomness test, symmetric distance, data cipher difference, encryption time, DES, HDES, DESX.