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Apple Begins Rejecting Apps for Using the Unique Device Identifier (UDID)

TechCrunch reports that Apple has begun rejecting iOS apps for the use of a unique device identifier known as the UDID. The site notes that several developers have reported rejections for the use of the UDID in the past week, and Apple is said to be ramping up the enforcement of this policy over the next few weeks.

As the name suggests, the UDID is a unique identifier for every iOS device. It's tied specifically to the hardware and can't be changed by the user. Apple had previously warned developers with the introduction of iOS 5 that the use of the UDID was deprecated and would be phased out. The sudden rejections, however, have caught some developers off guard:
“Everyone’s scrambling to get something into place,” said Victor Rubba, chief executive of Fluik, a Canadian developer that makes games like Office Jerk and Plumber Crack. “We’re trying to be proactive and we’ve already moved to an alternative scheme.” Rubba said he isn’t sending any updates until he sees how the situation shakes out in the next few days.
The reason for the phasing out of UDIDs from developer use is due to increased pressure on Apple due to the privacy implications. Apple and several App developers have been sued over the use of the UDID to track users across different apps. While the UDID doesn't specifically identify a user, the sharing of UDIDs across ad networks and apps can help piece together a valuable picture of activity and interests of the user of a specific device. Apple seems to be requiring apps to generate their own unique identifiers for each installation to avoid this ability to share such information across apps.

Top Rated Comments

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91 months ago
Why are developers "scrambling" for a solution to this? They've known for how many months exactly that this was coming?

Rating: 37 Votes
91 months ago

"We're trying to be proactive..."

Really? iOS 5 and Apple's warning have been out there for quite a while now. Seems at lot more reactive to me.
Rating: 36 Votes
91 months ago
How is using UDID a good idea for storing high scores, preferences etc? What happens when users upgrade to a new device?

yep, there are non ad uses for it.

The tough part is that if Apple doesn't allow a well defined transition period for it (where devs can still use the udid), users' apps that do use it for something like above (connecting a device to high scores, storage of preferences / data) will have their data lost on the next app update.


Rating: 26 Votes
91 months ago
How are developers "caught by surprise" and are "scrambling" as it is not exactly news. It sounds like apps are being rejected during the app review process so existing apps should be okay. The article makes it a bigger deal than it actually is.
Rating: 25 Votes
91 months ago
It's just not a good idea to use UDID for storing high score and other preference data. The high score and preference really belong to the user and not the device (users can have multiple or change devices) and the app should use a "user id" rather than a "device id".

If the app has proper customer service, they can do a simple score-transfer. The user would have to prove that they upgraded their device by either logging into their old or new device with their username. If the old device broke, it becomes a little harder to prove the identity of players, but IPs can also prove useful.

Rating: 20 Votes
91 months ago

give me a better way that doesn't require registration.


As I understand it, the problem with using the UDID is that it doesn't track your scores across devices. If you upgrade to a new iPhone, say goodbye to your highscores.

A better idea could be to just do it through Game Center, or being able to sync highscores to iCloud. You have to sign up if you want to use it for other things, anyways.
Rating: 18 Votes
91 months ago

give me a better way that doesn't require registration.


I think this is why Game Center has seen such popularity. No registration is needed assuming you already registered an Apple ID. Registration may not be the easiest method, but it clearly is the best in terms of flexibility, especially when the login is device-wide.
Rating: 17 Votes
91 months ago
iOS 5 was released to developers on June 6th, 2011. Apple announced the deprecation of UDIDs on August 18th, 2011 and this is there wording: "Deprecated in iOS 5.0. Instead, create a unique identifier specific to your app." That's 8 months ago. These are facts.

Looks like Apple not only gave enough advanced notice, but also told developers exactly what to do to workaround the problem.

Another article that only serves to exemplify the laziness, self-righteousness, and extreme sense of entitlement of some people.
Rating: 14 Votes
91 months ago
The developers who chose to use the UDID are making apps and I think it's the wrong thing to do in the first place because it won't survive device change/upgrade. People would already lose their high scores when they upgrade their device and now they would lose their high scores when they update the app on the same device as well.

I am not trying to be argumentative here. Just trying to illustrate that these problems could have been avoided with a little more thought on the developers side.

Of course, but we're not building an app here.

You just asked for why you would use UDID, and I gave you probably one of the biggest reasons. I'm not saying you would use it exclusively. Of course, you'd offer user registration too.

But, my point is. If you built a game using that technique (anonymous UDID high scores), all your unregistered users will lose their high scores on their next update.


Rating: 9 Votes
91 months ago
How can anyone possibly think that using UDID is a good thing?

I once used this free texting app on my iPhone3GS (after I had upgraded to the iPhone 4) that only used the UDID to identify the user. I sold the phone a few months later to a friend and he tells me one day that the app installed with my username and all of my texts that I had sent and received using the app. Really? People think that this is the optimum solution to getting around usernames and passwords? :mad:

Developers who use UDID are either lazy and incompetent at best or greedy at worst. The only people who advocate UDID are people who can financially benefit from tracking you.
Rating: 8 Votes

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