updated 05:55 pm EDT, Fri August 19, 2011
iOS 5 UDID API goes away, goes app-specific
A new discovery in iOS 5's documentation has raised concerns about the level of access developers will have to device information. Apple now considers the programming interface for the UDID, or unique device identifier, a "deprecated" technology in the new release, documentation forward to TechCrunch showed. Coders could still have unique identifiers, but they had to make their own app-specific IDs.
The reasoning for the change wasn't publicized. Privacy, however, is the most likely concern. Some advertisers and apps that want to tailor the experience use UDIDs. The two are convenient but also raise concerns that an advertiser could match up personal information with a UDID or otherwise identify a specific person.
Advertisers would be the most likely to object. They could create a consistent identifier approach that works across all of their apps, but they will have to drop UDID. The move would force them to blank out their ad histories.
Concerns persist as well that Apple might not necessarily behave fairly. Since it will always have access to the UDID, it could abuse access by getting UDID access where a developer wouldn't be banned, such as for an iAd campaign. Game Center could also use the identifiers in a way that third-party game networks might not.