If the history of mankind could be presented in the form of a spy novel, then the main characters of this work would undoubtedly be cryptographers and cryptanalysts. The first are specialists who master the art of message encoding. The second are geniuses of hacking and decryption, called hackers in computer slang. The history of rivalry between cryptographers and cryptanalysts is as old as the world. Evolving along with the development of high technology, the craft of encryption has reached in the 21st century the farthest frontier of modern science - quantum mechanics. And although the object of encoding is usually text, mathematics has been and remains the tool of encoding. This book is an attempt to tell the reader the history of encryption through the prism of the development of mathematical thought.