Apple is making a lot of changes in iOS 5, but one new change some developers are just starting to take notice, is something Apple is not talking about that much. In a documentation of iOS 5, Apple notes that it will be phasing out access to the unique device identifier, or UDID, on iOS devices such as iPhones and iPads.

This is a big deal, especially for any mobile ad networks, game networks or any app which relies on the UDID to identify users. Many apps and mobile ad networks, for instance, uses the UDID or a hashed version to keep track of who their users are and what actions they have taken. App publishers are now supposed to create their own unique identifiers to keep track of users going forward, which means they may have to throw all of their historical user data out the window and start from scratch.

Apple Documentation:
“uniqueIdentifier An alphanumeric string unique to each device based on various hardware details. (read-only) (Deprecated in iOS 5.0. Instead, create a unique identifier specific to your app.)”

9to5mac reported that “Apple likely will continue to use the UDID for its iAds, GameCenter, subscriptions and other services it offers across iOS devices”

One industry CEO thinks: “I guarantee Apple will not stop using UDID,” predicts one mobile industry CEO. If Apple does continue to use UDID for itself but denies it to developers that would be an “extremely lopsided change.” It would give Game Center and iAds yet one more advantage over competing third-party services.”

Source [TechCrunch]