GnuPG

 

GnuPG is a complete and free implementation of the OpenPGP standard as defined by RFC4880 (also known as PGP). GnuPG allows you to encrypt and sign your data and communications; it features a versatile key management system, along with access modules for all kinds of public key directories. GnuPG, also known as GPG, is a command line tool with features for easy integration with other applications. A wealth of frontend applications and libraries are available. GnuPG also provides support for S/MIME and Secure Shell (ssh). 

Using encryption helps to protect your privacy and the privacy of the people you communicate with. Encryption makes life difficult for bulk surveillance systems. The widespread use and availability of encryption software threatens the technological dominance that the economic and political elite have held for so long. Governments use encryption to protect their own secrets, such as those vital to "national security," but many of them try to limit access to encryption technology in order to surveill, censor, and otherwise control their citizens. ~ Therefore Encrypt!