About PGP With PGP™, you can protect the privacy of your email messages and files by encrypting them so that only the intended recipients can read them. You can also digitally sign messages and files, which ensures their authenticity. A signed message verifies that the information within it has not been tampered with in any way. PGP is based on a widely accepted encryption technology known as public key cryptography in which two complementary keys—a key pair—are used to maintain secure communications. To send someone a private email message, you use a copy of that person’s public key to encrypt the information, which only they can decipher by using their private key. Conversely, when someone wants to send you encrypted mail, they use a copy of your public key to encrypt the data, which only you can decipher by using a copy of your private key. You also use your private key to sign the email you send to others. The recipients can then use their copy of your public key to determine if you really sent the email and whether it has been altered while in transit. When someone sends you email with their digital signature, you use a copy of their public key to check the digital signature and to make sure that no one has tampered with the contents. © 1999 Networks Associates Technology, Inc.