Design principles of DES-like ciphers: A historical overview

ABSTRACT

This article gives a historical overview of the various design criteria of the Data Encryption Standard (DES) and some of its variants, starting from the legendary conditions given by Coppersmith in 1994. The authors follow their development until now, as simplified DES-like ciphers exist with improved properties. While doing so, they analyze the properties imposed on the S-boxes and the permutation used in the round function, and explain implications on the resistance of these ciphers against differential and linear cryptanalysis.

KEYWORDS:

• Coppersmith
• DES
• design principles
• permutation layer
• S-box

Acknowledgments

We would like to thank the anonymous referees for various helpful comments on an earlier draft of this article.

Notes

¹There are (2⁴)²⁶ = 2²⁵⁶ possible six bit to four bit boxes, which is comparable to the number of atomic particles in the observable universe.

Additional information

Notes on contributors

Daniel Loebenberger

Daniel Loebenberger obtained his doctorate in computer science from the University of Bonn in 2012. His interest ranges from algorithmic number theory to cryptography with a special focus on historical aspects thereof. Currently he researches and teaches cryptography at the Bonn-Aachen International Center for Information Technology (B-IT).

Michael Nüsken

Michael Nüsken obtained his doctorate in mathematics from the university of Konstanz in 1998. His interest ranges from computer algebra to cryptography. He worked at the university of Paderborn and since 2004 he researches and teaches cryptography at the B-IT.