Gpg4KDE was a product name to label a group of Free Software components that allowed end-to-end cryptography of emails and files on GNU/Linux systems. The label was in active use roughly between 2009 and 2020.
The main components were:
- GnuPG (Crypto engine)
- Kleopatra (GUI expert interface and widgets)
- KMail (Email)
- Dolphin (Filemanager) integration
Since then you can use either
- packages coming from your (trusted) GNU/Linux distribution
- for official government restricted data: check the offerings of https://gnupg.com labeled GnuPG VS-Desktop.
- see the AppImage with Kleopatra and GnuPG equivalent to the latest Gpg4win release from https://gnupg.org/download
Supported by several contracts since 2002, the German government, via its Federal Agency of IT Security (BSI) improved GnuPG to support what is now called cryptographic message syntax for use with S/MIME. All improvements were done as part of the upstream Free Software initiatives like KDE, GnuPG and mutt as much as possible.
- Ägypten2 Contract for example
Full groupware client with crypto email
2003 a Free Software groupware was build for the BSI, which used KDE's Kontact as its desktop client, including end-to-end cryptography.
For the some history of the Kolab Client see
Established around 2009-2010 installation packages were made available for Debian GNU/Linux Lenny mainly for:
- Kontact enterprise35 (including KMail1) using the KDE3 generation technology. (Still maintained to some extend as part of the Trinity Desktop Environment (as of Dez 2022)).
- Kleopatra (the GUI frontend component also based on KDE3 tech)
Thereby offering versions not yet available in Lenny, but necessary to gain fully uptodate OpenPGP/MIME and S/MIME support.
A common label was deemed useful at the time for describing a certain set and version numbers of software components that could be talked about with organisations, customers and that could be checked together.
Used for the initial certification
In 2019 a combination of a similar set of components (GnuPG, KMail2, Kleopatra, Dolphin-Plugin) was certified by the German "Bundesamt für Sicherheit in der Informationstechnik" (BSI) to allow for handling EU RESTRICTED (VS-NfD) data. Demonstrating that it is possible to officially handle government restricted data with Free Software components on GNU/Linux systems.