Slovak University of Technology, Bratislava
Faculty of Electrical Engineering and Information Technology
Degree Course: INFORMATICS
Author: Bc. Zuzana Cieniková
Diploma thesis: Generalized characteristic of S-boxes
Supervisor: RNDr. Karol Nemoga, PhD.
2002, December

The development of computers, internet, e-mail and mobile phones but also increasing protection of the information at organizations, categorization of security functions in the operating systems brings more new applications of the cryptographic systems.

Thesis is devoted to the development of the application of Feistel cryptosystem with S-boxes with generalized qualities. It contains the brief survey of Feistel-like cryptosystems, and of the universal qualities of S-boxes and of their design. It deals in more detail with the design of S-boxes with differential parameter 1, that use quasigroup without left unit.

At the conclusion it disserts about the quality of ciphertext with the use of these in the application of Feistel cryptosystem with variable number of S-boxes and rounds.