A symmetric cipher for West Africa: Bassam Symmetric Block Cipher (BSBC)

Abstract

In this paper, the authors presented a new symmetric block cipher, BSBC (Bassam Symmetric Block Cipher). BSBC is mostly the combination of the two standard symmetric block ciphers, DES (Data Encryption Standard) and AES (Advanced Encryption Standard), into a more powerful cipher. Indeed, for many years, DES has been the main standard for encryption, it is fast, easy to understand and simple to implement and well suited for hardware implementation. But most importantly, it uses the Feistel structure, which makes it a strong cipher. However, it is vulnerable to attacks like linear cryptanalysis, differential cryptanalysis, linear-differential cryptanalysis and rotational cryptanalysis. On the other hand, AES, which is the latest standard for symmetric block cipher, is robust against all these cryptanalysis attacks. The main drawback of AES is that its time, space and data complexity is quite high, which prohibits its implementation on smaller processors. Thus, the algorithm BSBC aims to include the strengths of both standards, while minimizing their disadvantages. That is, our algorithm is designed so as to withstand known cryptanalysis attacks while flexible enough to be implemented on small processors.In addition, the authors compared and contrasted the algorithm against the two standard for symmetric block encryption DES and AES with respect to Linear cryptanalysis, differential cryptanalysis and linear-differential cryptanalysis. A brief note on rotational cryptanalysis was also be provided.