Cryptography

Paper: DES96 – Improved DES Security

ABSTRACT

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.

Citation Information:

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).

Paper: DES80 – A DES Variant Cryptographic System

ABSTRACT

The Data Encryption Standard (DES) has shown noticeable weaknesses during the last decade. In this paper we develop a system that is a DES-variant but has more resistance towards the latest attacks against DES. The developed system has a sub-key generation algorithm that is totally different from the original DES one. The developed system uses a 70-bit initial key instead of the 56-bit key originally used. It has substitution boxes inside the key generation algorithm and mod2 addition. The choice of arrangement of substitution boxes in the main algorithm for each round is sub-key dependent. The result of our design is a DES-variant cryptographic system that has higher resistance towards brute-force attack, differential cryptanalysis, and linear cryptanalysis. Our design also canceled the weak-keys and complement-keys properties of the DES.
Citation Information:

Abdul-Karim A-R. Kadhim, Mohammed M. Alani, DES80: A DES-Variant Cryptographic System, published in the First Scientific Conference of the State Company of Internet Services, Baghdad, Oct. 22nd -23rd , 2002.

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Note: By the time we were working on this paper in the years 2000-2001, we had very limited Internet connectivity in Iraq. This lead to the fact that we did not know about the Canadian DES80 project at all. If we knew, we would have changed the name of the paper accordingly.