DESL algorithm (Menu Crypt/Decrypt \ Symmetric (modern) \ Further)

The DES variant DESL was first presented at the workshop on RFID security (RFIDSec) in 2006. DESL was designed by the Communication Security Group at the Ruhr University Bochum with a minimal footprint of the cipher in hardware in mind. The designer decided to adapt DES since it is probably the best investigated cipher in existence. In the last three decades since DES was first announced only three analytical attacks have been found:

Furthermore, contrary to most symmetric ciphers, DES was designed with good hardware performance in mind rather than good software performance. Note that chip technology at the time DES was designed (early 1970s) was very constrained compared to today’s hardware. This fact can also be observed looking at the low number of transistors required for a DES hardware realization (compared to other symmetric ciphers).

In order to further reduce the number of gates the 8 different S-boxes of DES were replaced by 8 identical ones. Therefor a cryptographic very strong S-box was chosen, such that the Davies-Murphy attack as well as the linear and differential cryptanalysis are now infeasible. Furthermore the designers omitted the initial permutation (IP) and its inverse (IP-1), because both permutations do not influence the cryptographic properties of the cipher.

There are various applications for DESL imaginable, ranging from RFID tags to resource constrained devices in general.

One problem of DESL is its short key length of 56 bit. To cope with this, analog to DESX the variant DESXL was proposed.

For further information see: http://www.crypto.rub.de/en_publications.html

Also see: DESX, DESXL