From what I can tell the UDID lock is not actually secure enough and is not designed to be a critical path around the encryption algorithm.<p>An earlier comment with more technical detail: <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=11141499" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=11141499</a><p>UDID lock is good enough for tying development builds to specific devices but is not an unbreakable guarantee the software cannot be run on another device.