Introduction to Cryptography

People mean different things when they talk about cryptography. Children play with toy ciphers and secret languages. However, these have little 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. Strong encryption used to be only military business; however, in the information society it has become one of the central tools for maintaining privacy and confidentiality. As we move into an information society, the technological means for global surveillance of millions of individual people are becoming available to major governments. 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. It is time to de-mystify cryptography and make full use of the advantages it provides for the modern society. In the following, basic terminology and the main methods of cryptography are presented. Any opinions and evaluations presented here are speculative, and neither the authors nor SSH can be held responsible for their correctness - although every attempt is made to make sure that this information is as correct and up-to-date as possible.