Typically we recommend implementing some sort of authentication scheme at run-time, however the implementation of that is up to you. There are a variety of examples posted on password protecting LabVIEW built applicaitons. Here are a few of them, hope this helps! The one we recommend is the first option, but some of the other examples offer more functionality and flexibility.
Password Protect LabVIEW Applications at Run-Time
http://digital.ni.com/public.nsf/allkb/A3A3312AAEF4CC5286257558007E8B22
How to create login and password for my application
http://forums.ni.com/t5/LabVIEW/how-to-create-login-and-password-for-my-application/td-p/787166
LabVIEW and Windows Authentication
http://lavag.org/topic/15260-labview-and-windows-authentication/
Hope this helps!