I am designing a Point-Of-Sale system for a small shop. The shop just have one Point-Of-Sale but often they are one to three users (sellers) in the shop. Each user have their own user account in the system so they login and logout very often. How should I design the login/logout system in a good way?

For the moment the users don't use passwords, because it takes so long time to type the password each time they login.

The Platform is Windows Vista but I would like to support Windows 7 too. We use Active Directory on the Network. The system is developed in Java/Swing for the moment, but I'm thinking about to change to C#.NET/WPF.

I am thinking about an SmartCard solution, but I don't know if that fits my situation. It would be more secure (which I like) but I don't know if it will be easy to implement and smooth to use, i.e. can I have the POS-system running in the background or started very quickly when the users switch? Are SmartCard solutions very expensive? (My customers are small shops) Is it preferred to use .NET or Java in a SmartCard solution?

What other solutions do I have other than passwords/no passwords/smartcards?

• How should I design the login/logout system in a good way?
• Is there any good solution using SmartCards for this purpose?
• I would like suggested solutions both for C#.NET/WPF and Java/Swing platforms.
• I would like suggested solutions both for Active Directory solutions and solutions that only use one user profile in Windows.

How is this problem solved in similar products? I have only seen password-solutions, but they are clumsy.