gpg in linux

full name:
	The GNU Privacy Guard
	
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).

Since its introduction in 1997, GnuPG is Free Software (meaning that it respects your freedom). 
It can be freely used, modified and distributed under the terms of the GNU General Public License .