Computer Security and Public Key Cryptography

Abstract

The problem of computer security arises in several contexts in this modern age where most computers are connected to the Internet. Being connected is of course valuable but it also means that the computer is liable to invasion by unfriendly external agents (sometimes called hackers) which inject viruses, which are insidious programs that can insert themselves into a computer’s operating system and cause serious damage in its executable functions and also possibly access confidential files. This raises problems in computer security. The problem of virus protection is treated by several software companies who sell their products to the computer owner. In this chapter, we are interested in another aspect of computer security which the computer owner can deal with directly. This is the problem of confidential (or secret) encrypted email. We have already mentioned that Turing worked on cryptography in World War 2.