Data encryption standard visual representation

This paper describes a method for visual representation of Data Encryption Standard (DES) algorithm. The described method was implemented in the COALA (CryptOgraphic Algorithms visuaL simulAtion) system, which was developed at the School of Electrical Engineering, University of Belgrade. The COALA system is designed to help students who study Computer security course to better understand one of the core topics, i.e. cryptographic algorithms. Some major problems considering the visual representation of the DES algorithm are elaborated in the paper. The manner in which these problems were overcame in the COALA system and the specifics about the implementation of the DES algorithm are explained. At the end a short discussion on the effects of the COALA system in education and directions for future work are given.