These days using the Internet and E-mail is common, easy, and even a necessity for some of us. But have you ever wondered if that E-mail you just read was really from the person you thought is was from? It might have been from someone else who was using that persons account, or who set up their E-mail program to show a different name. It might even have been sent by a virus. Of course the same is true about messages others think were sent by you.

Did you know that the message you just sent could be read by anyone with the right access to a computer along the message's path? Thats right, that E-mail you just sent and thought no one but the recipient would see might have been read by some stranger or perhaps even someone you or the recipient knows. Their are four main locations where messages get intercepted: your computer (the sent/out box), your SMTP server where the message gets held until sent to the destination, the recipients mail server where the message is stored until deleted, and finally the recipients computer. There is a fifth location, any computer the message has to pass through on its from you to the recipient could intercept copy and even alter the message. Remember E-mail is sent as a plain text message readable by anyone.

Both of these problems can be solved using digital signatures and encryption. In fact your E-mail program probably already supports one of the two most popular forms. Microsoft products and Netscape directly support the S/MIME using digital certificates from companies like Verisign and Thawte. Mozilla will eventually support S/MIME. PGP was the original signature and encryption program. It has plug-ins to add PGP support in Eudora, Outlook, and Outlook Express. While it used to be popular on Linux and other *nix systems it has since been replaced on all platforms by GPG which is based on the Open-PGP standard.

Both systems require the use of digital certificates. S/MIME certificates are generally issued by a certificate authority (CA) such as Verisign or Thawte. Because the CA must verify your ID before issuing the certificate they usually charge money for them. The more capabilities the certificate has such as code signing or e-commerce, the more verification is needed, the higher the cost. This is a yearly fee since the certificates expire after one year. PGP/GPG certificates on the other hand are created by you. This means you can create as many as you want which is most useful when you have more than one E-mail account and don't want to use the same certificate for all of them. The owners ID is verified by checking the signatures on the certificate. More on this can be found at the GPG site.

Key ID:      0x06D4E7D1
Fingerprint: 1CC1 2471 0095 A595 944D 504A 0CCA EAE0 06D4 E7D1

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Version: GnuPG v1.4.9 (MingW32)

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-----END PGP PUBLIC KEY BLOCK-----