Login in the system using a physical key. How to do?

Question

ubuntu

The essence of the task is as follows:
There is a working laptop with Ubuntu 14.04. It is necessary to deploy a certification authority on it to authorize the user using a physical key (a regular flash drive with a written key certificate).
Who faced such a task, please help / suggest / poke your nose into the manual.
UDP: Required:
1. Login with USB stick;
2. When the USB drive is removed, it will automatically lock;
3. Automatic reverse process when you connect this carrier;

Answer 1

Here can so
Try and unsubscribe if it turned out.
Update
for the first two points, this is suitable for
the third point, while the question ...
Update-crutch for locking-unlocking,
enter
gsettings set org.gnome.desktop.a11y.applications screen-keyboard-enabled true
we get the on-screen keyboard after loading and logging in, but then it's ok...

Answer 2

ubuntuforums.org/showthread.php?t=1447218