Library

There is a kind of battlefield without gunpowder smoke, but there is killing, which is a more cruel destruction of human nature. There is a group of heroes who have no names, only codenames, but their deeds will be remembered forever. Crypto warfare, the lurking wisdom of deciphering, espionage warfare-conspiracies deep behind enemy lines. A book to understand the principles of making and deciphering military war codes. One book reveals the essence of espionage wars involving multiple countries' complex spies, counter-espionages, multiple spies, and mission-impossible espionage. A book commemorating and celebrating the countless unsung heroes who fought for victory.