The Data Encryption Standard (DES) has shown noticeable signs of aging during the last two decades. In this paper we develop a system that is a DES-variant with more resistance towards the possible attacks against DES. The developed system has a sub-key generation algorithm that is completely different from the original DES.
The developed system uses 84-bit initial key instead of the 56-bit key originally used. It has substitution boxes inside the key generation algorithm and mod2 additions. The choice of arrangement of substitution boxes in the main algorithm for each round is sub-key dependent. The result of the design is a DES-variant cryptographic system that has higher resistance against brute-force attack, differential cryptanalysis, and linear cryptanalysis. The proposed system design also cancelled the weak-keys and complement keys properties of the DES.
Index Terms – data encryption standard, encryption, cryptanalysis.
Mohammed M. Alani, DES96 – Improved DES Security, Proceedings of the 7th IEEE International Multi-Conference on Systems, Signals and Devices (SSD’10) , Amman, Jordan. June 2010. (IEEEXplore).