shaders/push-notifications-sdk — pull request #4 by nferruzzi (2012-12-17 20:42:01+00:00)
Title: uniqueGlobalDeviceIdentifier on iOS6

Hi,

this is a privacy fix, basically the hwid generated from md5 of a mac address is exposing the mac address itself to the backend servers that need to store it.
A simple MD5 does not provide any protection and its almost like using the value itself because Apple mac address ranges are public (http://standards.ieee.org/develop/regauth/oui/public.html) and they can be used to inverse mapping all hwid to mac address in a matter of hours with just modern hardware.

For this reason using mac address should be discouraged. Apple provide a new api for ios6 and my patch use it. There is of course the same problem on iOS5, I don't have the code for it right now but the solution would be to generate a UUID and store it on keychain. Of course this won't be "device" unique like the old deprecated uniqueIdentifier but at least it won't leak any information with it.

hope you may be interested