Pretty Good Privacy (PGP)

To use Pretty Good Privacy, download or purchase it and install it on your computer system. It typically contains a user interface that works with your customary email program. You may also need to register the public key that your PGP program gives you with a PGP public-key server so that people you exchange messages with will be able to find your public key.

PGP freeware is available for older versions of Windows, Mac, DOS, Unix and other operating systems. In 2010, Symantec Corp. acquired PGP Corp., which held the rights to the PGP code, and soon stopped offering a freeware version of the technology. The vendor currently offers PGP technology in a variety of its encryption products, such as Symantec Encryption Desktop, Symantec Desktop Email Encryption and Symantec Encryption Desktop Storage. Symantec also makes the Symantec Encryption Desktop source code available for peer review.
Though Symantec ended PGP freeware, there are other non-proprietary versions of the technology that are available. OpenPGP is an open source version of PGP that’s supported by the Internet Engineering Task Force (IETF). OpenPGP is used by several software vendors, including as Coviant Software, which offers a free tool for OpenPGP encryption, and HushMail, which offers a Web-based encrypted email service powered by OpenPGP. In addition, the Free Software Foundation developed GNU Privacy Guard (GPG), an OpenPGG-compliant encryption software.