usability: unlocking screen resp. login screen

[Markus Lutzer]

Dear developers,
in the following I formulated some suggestions for Ubuntu with usability
in mind:

Unlocking screen saver:
-----------------------
Currently my Ubuntu system asks me for my password when I come back
after a while to unlock the screen saver. This is alright for a single
user system but if another user wants to use the system while the first
has locked the screen the usability is too much complicated: At the
password prompt the user has to press a button to change user, then the
user has to select its user name from a list of available users,
afterwards he is confronted with the default login screen where the user
has to enter its user name a second time (!) and then his/her password.
Windows solved this issue much more user friendly: The user is
confronted with one login screen only (and not with three different
ones) whatever the user wants to log in the first time, unlock the
screen saver or log in a second time resp. changing the user. Why not to
follow this approach which has a much better usability?

Login screen:
-------------
The above does not require to replace the current default login screen
with a login screen allowing to select a user from a list but I would
recommend this additionally. It would be much more comfortable for the
average user to have a list of available users ("aeh, ouh! What was my
user name anyway?") because
(1) she/he has an overview which users are already registered and can
choose one,
(2) she/he can not forget his/her user name,
(3) it avoids typos, allows to use the system more quickly and
(4) is more similar to Windows which many users know already.

The security implications are minor because
(1) security should depend on the password, not on the user name (Shall
I choose a strong user name and not a simple one??!),
(2) accessing an Ubuntu system with an active screen saver shows me all
available users anyway,
(3) the user name can often be guessed easily and
(4) usages with high security requirements need to configure Ubuntu
anyway but not the average desktop user for who a user list is
sufficient secure.

I would be glad if you are interested in my suggestions and reply with
your ideas.

Markus