I'm registering the devices of my app users with a third-party push notification service.
I need to associate each device with its user at the service so that I can target a specific user's devices when sending a notification.
I could associate the device with the user's database Id, but I'm inclined to use a special GUID identifier in order to hide the user's database key.
I reckon the database key could leak information about the system, including a hint as to the number of users of the system.
Does this sound unnecessary?