There are a lot of ways to do this. The easiest way off hand I can think of is - ask your user for their roku's serial number, and hard code it within your roku app itself. If anyone else tries to use it, it won't work because your serial number check will fail when they run it on a different roku. You can change the serial in the pkg for each person allowed to use your channel, or include multiples in the app itself.
Otherwise, you can have it prompt for a password on execute, or check your server database for a list of authorized passwords, or check IP addresses of requests on the server, or check certificate authentication keys, or check for an ascii file connected to USB on the roku, or or or... lots of possibilities.
Sub RunUserInterface()
currentserial=CreateObject("roDeviceInfo").GetDeviceUniqueId()
if currentserial="13A16X123456" then intheme()
End Sub
Sub intheme()
'user device id is authorized, app starts here
End Sub
