MATLAB-based module for encryption and decryption using bifid ciphers applied in cryptosystems

The paper describes an algorithm and developed MATLAB-based module with options for interactive e-learning for encryption/decryption of texts using bifid ciphers. It will be used in the course “Telecommunications Security”, included as compulsory in the curriculum of the specialty “Telecommunication Systems” for Bachelor degree at the University of Ruse. The application allows selecting the language and the parameters of the encryption/decryption key through menus. It illustrates step by step the process of encryption/decryption of the plain-text/cipher-text entered by the user, using bifid ciphers. The novelty is that the algorithm for encryption/decryption of texts in English using bifid ciphers is modified to be used for texts in Bulgarian, Russian and Romanian. The module has a possibility to display information on bifid ciphers and to illustrate the principle of its operation in a separate graphical window.