The book starts by explaining steganography and cryptography. Steganography is the process of hiding a message, while cryptography is the process of hiding its meaning. Examples of both are given with information on how the codes are used, and how they were broken. The main example is Mary Queen of Scot's code, the weakness of which led to her execution. Later, the book moves onto stronger forms of encryption such as the Vigenere square and …showed first 75 words of 826 total…

…showed last 75 words of 826 total…used to cover encrypted information; examples are available over the Internet. For this reason, there can be practically no legal possibility of control to prevent a wide exchange of encrypted information. A law will not affect criminal users, since the necessary software can be used without substantial cost. It will remain generally available even if a law is passed. As is the case in all areas of society, technical progress brings both advantages and disadvantages.