Pretty Good Privacy (PGP)
Now that you understand how PGP can be used, read this article to learn who developed PGP while taking note of the year it was developed. Be sure to read the sections on how PGP works as well as the encryption-decryption process using the public and private keys. As you will notice, the public keys versions are RSA that was previously discussed, and Diffie-Hellman that will be discussed in a later section.
Pretty Good Privacy can be used to authenticate digital certificates and encrypt/decrypt texts, emails, files, directories and whole disk partitions. Symantec, for example, offers PGP-based products such as Symantec File Share Encryption for encrypting files shared across a network and Symantec Endpoint Encryption for full disk encryption on desktops, mobile devices and removable storage. In the case of using PGP technology for files and drives instead of messages, the Symantec products allows users to decrypt and re-encrypt data via a single sign-on.
Originally, the U.S. government restricted the exportation of PGP technology and even launched a criminal investigation against Zimmermann for putting the technology in the public domain (the investigation was later dropped). Network Associates Inc. (NAI) acquired Zimmermann’s company, PGP Inc., in 1997 and was able to legally publish the source code (NAI later sold the PGP assets and IP to ex-PGP developers that joined together to form PGP Corp. in 2002, which was acquired by Symantec in 2010). Today, PGP encrypted email can be exchanged with users outside the U.S if you have the correct versions of PGP at both ends.
There are several versions of PGP in use. Add-ons can be purchased that allow backwards compatibility for newer RSA versions with older versions. However, the Diffie-Hellman and RSA versions of PGP do not work with each other since they use different algorithms. There are also a number of technology companies that have released tools or services supporting PGP. Google this year introduced an OpenPGP email encryption plug-in for Chrome, while Yahoo also began offering PGP encryption for its email service.