Is it possible to bundle a unique file for each copy of iPhone app downloaded from App Store?

I would like to verify the identity of each instance of the iPhone application that a user might use to conne开发者_StackOverflow社区ct to my service. To that end, I would like each instance of the iPhone app downloaded to include a certificate that I generate, or even some sort of UUID that I have generated. Does the App Store support the inclusion of unique files in an app bundle?

Or, must such identifiers be downloaded only after the app is installed? If that is the case, is there a mechanism to ensure that the app downloaded is trusted (from me), instead of from an impersonator?

I don't think it's possible to have unique packages per download. Why don't you use the UUID of the device for such checks?