Configuration
comes with a control module named kcmkdesu. You can find it in the K menu under Settings Applications KDE su. You can change the following things:
Echo Mode 	This is how characters you type are echoed to the screen. Possible choices are: one star per character, three stars or no echo at all. The default is one star per character.
Keeping passwords 	You can instruct remember passwords you enter by checking the keep password check box. If this checked, you can enter a timeout value in the text field below it. This is the amount of time, in minutes, that the password will be remembered. The default is not to remember passwords.