Apple Phasing Out Use of Device Identifiers to Track Users on iOS 5

Apple instructs its developers to implement other ways to track user behavior and collect data and not use the Unique Device Identifier in iOS 5.

Apple has told software developers to stop using the unique identifier that would allow companies to track users and their behavior when developing iPhone and iPad apps.

The Apple Website for iOS developers said the use of the Unique Device Identifier will be "deprecated" in iOS 5, TechCrunch reported on Aug. 19. Apple just released iOS 5 beta 6 to developers, and the final release is expected later in the year.

Use of an "alphanumeric string unique to each device based on various hardware details" will be "deprecated" in iOS 5, Apple said on the developer Website. Developers can still create their own unique identifiers for their apps, Apple said. The app-specific mechanism would work like Web cookies.

The use of the word "deprecated" rather than "discontinued" or "banned" is intentional in this announcement. It indicates that Apple is discouraging the practice of using the Unique Device Identifier without technically preventing its use.

While the capability will still exist in iOS 5 and can be used, Apple recommends that developers avoid implementing the UDID as the "feature has been superseded and may become unsupported in the future," according to the Website. Deprecated features tend to stay in a few versions to support older devices as well as to give developers time to remove the features from existing apps, according to developers who spoke with eWEEK.

Developers, companies and advertiser networks rely on the 40-digit unique combination of letters and numbers to find out what their users are doing on the devices beyond the specific app. The UDID is specific to each Apple device and can be used to gather saved user data as well.

The change will impact how advertising networks, game networks and analytics firms identify users. Advertising networks depend on the UDID to target users with relevant ads and to track whether the user has already seen or clicked on an ad.

Apple may be responding to privacy concerns about how the data collected can be used to track user behavior without their awareness or consent. Recently, the Wall Street Journal found that of the 101 popular iPhone apps and Android apps it tested, 56 transmitted the phone's unique device ID to other companies without the users' knowledge.

That revelation prompted at least two lawsuits from Apple consumers, accusing the company of letting advertising networks track users. The UDID "allows the downloaded applications access to the user's browsing history each time the user clicks on an advertisement or application appearing on their mobile device," said court documents file for one of the suits.

The change may make it more difficult for app developers to market their programs to advertisers and other companies that rely on data gathered via UDID. With apps moving away from UDID, it will be harder for developers to persuade advertisers to sponsor the app, which may also have an impact on pricing. If the advertiser dollars dry up, developers may have no choice but to raise their prices.

Developers can download their own cookies and force users to register an account. It may be possible to use iCloud and its Documents and Data feature to story key values in the cloud that would be used for tracking. GameCenter also allows third-party apps to associate a user with a specific state within a game; the mechanism might be adapted for apps just as well.