Sorry, I don't think this strategy is workable. Consider - 74% of apps I tested sent the UDID to one or more upstream servers. Furthermore, Flurry alone receive

Sorry, I don't think this strategy is workable. Consider - 74% of apps I tested sent the UDID to one or more upstream servers. Furthermore, Flurry alone received UDIDs from 15% of apps I tested. That's just one aggregator, and they surely have nearly 100% of UDIDs on file. The APNS tokens narrow it down somewhat, but not too much. It's also not at at all clear that there is a single source involved - this could be an amalgamation of a number of sources. See this post for the source of these figures: http://corte.si/posts/security/apple-udid-survey/index.html http://corte.si/posts/security/apple-udid-survey/index.html