PGP, or Pretty Good Privacy, first appeared on the Internet in 1991. 
It 
has enjoyed significant popularity amongst the Internet Community.

PGP is used both for protecting E-mail and File Storage. It presents a 
way to digitally sign and encrypt information "objects." As such it is 
well suited for any store and forward application.

The goal of the OpenPGP working group is to provide IETF standards for 
the algorithms and formats of PGP processed objects as well as 
providing 
the MIME framework for exchanging them via e-mail or other transport 
protocols.

Because there is a significant installed base of PGP users, the 
working 
group will consider compatibilty issues to avoid disenfranchising the 
existing community of PGP users.

Security Issues:

The whole purpose of Open-PGP is to provide security services.