Information
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock.
The session lock is implemented at the point where session activity can be determined and/or controlled.
Solution
Configure the operating system to initiate a session lock after a 15-minute period of inactivity for graphical user interfaces.
Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command:
# touch /etc/dconf/db/local.d/00-screensaver
Add the setting to enable screensaver locking after 15 minutes of inactivity:
[org/gnome/desktop/screensaver]
idle-activation-enabled=true
Update the system databases:
# dconf update
Users must log out and back in again before the system-wide settings take effect.