I have set up this page in response to questions I get about PGP - what it is, where to get it, and how to use it. Its public-key cryptography system enables people who have never met to secure transmitted messages against unauthorized reading and to add digital signatures to messages to guarantee their authenticity. E-mail sent over the Internet is more like paper mail on a postcard than mail in a sealed envelope. It can easily be read, or even altered, by anyone with privileged access to any of the computers along the route followed by the mail.
Government agencies eavesdrop on private communications.
More detailed information about PGP, and copies of the program itself for various platforms, can be found from the links given below. There is considerable overlap between these tutorials. If you don't find the information you need in one of them, try another, or try the FAQ . The proliferation of different PGP versions can be rather confusing. The first two versions do the same thing, though the international version has certain minor advantages.