In addition to its encryption capabilities, PGP allows you to sign your e-mail message so that the recipient knows that it is from you. To sign the message, follow the steps listed above with one exception. Instead of choosing Encrypt, select Encrypt and Sign. Then follow the same steps to choose the public key with which you wish to encrypt the message. PGP will prompt you to use your Private key as a signing key. Enter the password for your private key. PGP will encrypt the message with the Public key and sign it with your Private key. A signed message, when decrypted, will look like this:
*** PGP Signature Status: good
*** Signer: Zenwolf <Zenwolf>
*** Signed: 3/13/2000 1:42:11 PM
*** Verified: 3/13/2000 1:46:21 PM
*** BEGIN PGP DECRYPTED/VERIFIED MESSAGE ***
This is a test of PGP using a signed message.
*** END PGP DECRYPTED/VERIFIED MESSAGE ***
Exchanging Public Keys
Now we know how to encrypt and decrypt e-mails sent with PGP, but how do you send and receive Public keys so you can communicate with other people using PGP? There are several ways to do this.
When you installed PGP there was mention of sending your Public key to a PGP Public Key Server. A PGP Public Key Server is an Internet depository of Public PGP Keys. Many experienced PGP users use PGP Public Key Servers to make it very simple for others to obtain their public keys as well as to avoid having to manually send out their Public keys to everyone who asks.
Another way and perhaps the most popular way to exchange PGP Public keys is via e-mail. To send someone your Public PGP key, open PGPkeys, highlight your key and select Keys, then choose Export and save this file. When you need to send someone your Public Key, simply send this as a file attachment to that person and then they can add your key to their key ring. Now how do you add someone’s Public key to your key ring? Once you have received their Public key open PGPkeys and select Keys, then Import. Choose the key from where you saved it and it will be entered into your key ring. You can then use it to send encrypted messages to that person.
Now you can use PGP to encrypt and decrypt your e-mail messages. It is not that hard to do and once you have done it a few times it becomes second nature. Encryption not only insures the privacy of your e-mail, it also serves to positively identify the sender of correspondence you receive. You can pick up your free copy (for private non-commercial use) of PGP from MIT here: http://web.mit.edu/network/pgp.html.
– zenwolf –