iOS6 UDID - What advantages does identifierForVendor have over identifierForAdvertising?

Question

Apple is changing their privacy settings for iOS6 and deprecating device UUIDs (UDIDs). According to a WWDC presentation and the docs there are two replacements for the UDI

Answer 1

Those APIs are so badly designed, that clearly says - Apple does not want us to identify user devices.

Just look at the identifierForVendor description.

It is erased if the user erases all apps from the same vendor. :( It is not reliable - can return nil (documentation advices to "wait" for some time if this happens. :(

They did not use obvious solution, which works anytime and does not rely on installs/removes - return SHA-1 (or any other hash) of internal hardware device id concatenated with Team ID.

Answer 2

User can change identifierForAdvertising any time in Settings, identifierForVendor changes after reinstall app, if no more apps on device from this vendor.

Here is alternative and the best solution for get or persistent, cross-install Device Identifier:

description: https://blog.onliquid.com/persistent-device-unique-identifier-ios-keychain/

code: https://gist.github.com/miguelcma/e8f291e54b025815ca46

Answer 3

Important Note:

Apple just released iOS 6.0 and the NDA has been lifted.

For developers who preemptively included code that referenced

[[UIDevice currentDevice] identifierForAdvertising]

this method has NOT been included on iOS 6. If you use the above method, your app will (most likely) crash and be rejected!

Instead, Apple has created a new class ASIdentifierManager , which includes the method advertisingIdentifier. Here's the apple docs on it:

Answer 4

Users can limit the use of ad tracking on their phone. See this article on the opt-out mechanism under Settings > General > About > Advertising.

The new ASIdentifierManager class has a property advertisingTrackingEnabled, which returns true or false depending if the user has limited ad tracking. Even though the device's advertising identifier is returned by the advertisingIdentifier property regardless of opt-out, you aren't supposed to use the identifier if the user has opted-out.

So the advantage of identifierForVendor is that you'll always have access to and the right to use this id for the phone regardless of user's opt-in or opt-out for advertising tracking.

Answer 5

Use the VendorID. This is a very enlightening article http://www.doubleencore.com/2013/04/unique-identifiers/

Answer 6

To create a uniqueString based on unique identifier of device in iOS 6:

#import <AdSupport/ASIdentifierManager.h>

NSString *uniqueString = [[[ASIdentifierManager sharedManager] advertisingIdentifier] UUIDString];
NSLog(@"uniqueString: %@", uniqueString);