The purpose of the course is to introduce students with the basic principles of Cryptography knowledge and its application for the information’s protection in modern computer systems. The course is more applied oriented and includes: Stream and Block Ciphers, DES algorithms, AES algorithms, Public cryptographic key algorithms, RSA algorithms, Digital signatures and Certificates, Hash functions. The most commonly used cryptographic algorithms in communication, web, and mobile application software are discussed. Basic principles, procedures, block diagrams, cryptographic keys and their management and exchange are presented. The acquired knowledge can be used in practice to solve the problems related to providing reliable cryptographic protection in various fields - computer networks, e-business, banking, electronic payment systems, GSM communications, encryption of speech signal and more.