If you need to lock a PDF file with a password on Linux, there is an easy way to do it even if it requires a terminal.
Security
Keep track of your SSH sessions in Gnome
In the past we discussed how to generate SSH keys on Windows using PuTTY and how to generate SSH keys on Linux using ssh-keygen, and now we see how you can track your SSH connections in Gnome.
Generate SSH keys on Linux using ssh-keygen
Last week I have illustrated how to Generate SSH keys on Windows using PuTTY, now I will explaining you how to generate SSH keys on Linux using ssh-keygen.