GnuPG Software Description
GnuPG is a file and email encryption software that allows you to encrypt files and emails for yourself, so you don’t have to worry about security. It is used by the majority of file encryption software and can be used with the mail client Thunderbird. It uses OpenPGP (RFC 4880) and OpenPGP public APIs. It is a command-line tool, but there are many graphical user interfaces, depending on the operating system, including Gpg4win, Enigmail, Gpg4usb, and Mailvelope.
It can be used to encrypt data and create digital signatures. It includes an advanced key management facility and is compliant with the proposed OpenPGP Internet standard as described in RFC2440. It is often used together with GNU Privacy Guard or GPG, the de-facto standard implementation of the OpenPGP protocol.