The course invites you to learn more about cryptography; you'll learn some important math which stands behind the ciphers, and defines how resistant the particular cipher will be to different types of attacks. The key topics covered in the course: * how cryptography developed in Russia and in the Soviet Union, including the facts which used to be top secret until very recent times; * Boolean functions and S-boxes, and how the resistance of a cipher depends on a cryptographic properties of a Boolean function; * methods of cryptanalysis * some special and most intriguing types of cryptographic Boolean functions: bent functions and APN-functions (Almost Perfect Nonlinear Functions) * AI and ML for cryptography. Welcome to the course, and enjoy your learning!