I have an Ubuntu 18.04 server and my gpg (GnuPG) version is 2.2.4.Ĭan anybody help me out how to do that? It must be rather simple but I wasn't able to do manage it. I tried to follow a few tutorials I found on the internet to do so but none of them worked so far. For a user testUserX, which I still have to create, I want him (testUserX) to use the authenticate subkey for the login onto this server. I created a PGP master key and an authenticate subkey on my Ubuntu server.