The most common use for PGP is to sign messages or verify the origin of messages you receive. We're going to be using Eudora, because that's what Cynthia uses, but the same procedures should work for any email client.

Please be sure that you are not using HTML for your email messages. That can interfere with PGP-signing messages and result in invalid signatures. Use only plain text.

Cynthia has created a new email message to send to Jayne.

After she has composed the email message, Cynthia leaves her cursor in the body of the message, hits Ctrl+A to select all of the message, then hits Ctrl+Shift+S (the hotkey to sign the contents of the current window). If she had not enabled the hotkeys, she would hit Ctrl+A to select all of the message, then Ctrl+C to copy the message into the clipboard, then used the clipboard options of PGPTray.

Either way, the software will ask for the signing passphrase.

After entering the passphrase, PGP signs the message, then (if the hotkey was used), automatically replaces the original text with the signed text. If the clipboard option was used, Cynthia would have put her cursor back in the body of the message, hit Ctrl+A again, then hit Ctrl+V to paste in the new material.

Cynthia sends the message on to Jayne.

Next: Verifying PGP Signatures