Moodle Partner ED-ROM is maintaining this novel Moodle authentication plugin for the community which ensures that all users can only have one active session on your Moodle site. Unique Login, recognizes and prevents two individuals from logging into the same user account on your site simultaneously which can help to prevent two types of issues:
- unauthorized access which occurs when a student forgets to logout of their Moodle account (and another user jumps on the same computer)
- collusion and other collaborative cheating which can occur when a user willingly shares their credentials with a third party (though this is merely an obstacle since the 3rd party could continue uninhibited as long as they are the sole user)
You can download the supported authentication plugin here: https://moodle.org/plugins/view.php?plugin=auth_uniquelogin.
The Plugin is available for Moodle 1.9 and up.