GPG (Gnu PGP) is a good way of encrypting and verifying that the data really belongs to the said person, and here's how i did it on my mac.
Install GPG
http://www.gpgtools.org/installer.html
From the shell[Terminal]. ($)
Tip 1.) To Generate your own GPG Key (Follow the instructions after running the command below. Keep the Default DSA Elgamal Encryption) and viola! you have your own gpg key.
$gpg --gen-key
Tip 2.) To Verify your key
$gpg --list-secret-keys
Tip 3.) Exporting your GPG Key (good for Emails)
$gpg --output MyGPGKey.pgp --export john@doe.email
Tip 4.) Exporting your GPG Key (for Public Display website, etc.)
$gpg --output MyGPGKey.pgp --export john@doe.email --armor
Tip 5.) Importing someone else's GPG Key (Extensions sometimes come as .asc or .gpg)
$gpg --import foobar.asc
Tip 6.) To Validate GPG Keys from others
$gpg --edit-key john@doe.email
Tip 7.) To send your key to a public GPG Server (GPG ID is found on the sec portion of the output for Tip #2)
$gpg --send-keys GPG ID
Keep safe on the Internet