Cryptosystems Preface People mean different things when they talk about cryptography.
Children play with toy ciphers and secret languages.
However, these have nothing to do with real security and strong encryption. Strong encryption is the kind of encryption that can be used to protect information of real value against organized criminals, multinational corporations, and major governments. As we move into an information society, the technological means for global surveillance of millions of individual people are becoming available to major govenments. Cryptography has become one of the main tools for privacy, trust, access control, electronic payments, corporate security, and countless other fields. Cryptography is no longer a military thing that should not be messed with.