Pretty Good Privacy (PGP)

In 1991, Pretty Good Privacy (PGP) was released by Phil Zimmerman, an American. To this day, it is considered a very secure way of communication across the internet. PGP employs a public key system so that the a recipient cannot determine the key used to encrypt the message, even if he knows the key for decrypting the message.  PGP is designed so that it can be integrated into email packages, thus allowing it to be used by the average citizen.