Here's Everything We Know About IFA, The iPhone Tracking Technology In Apple's iOS 6

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Photo: SharonaGott / flickr

Apple consumers are a dedicated bunch, but how do they feel about advertisers tracking their every move while using their beloved iPhones and iPads?Although Apple allows users to limit ad tracking within its new operating system, iOS 6 — here’s an easy how-to — we still don’t know a lot about what advertisers can see and do with the new Identifier for Advertisers (IFA or IDFA)

Here’s a guide to everything that’s currently known about IFA.

Bye Bye UDID

  • Prior to iOS 6, Apple products used Unique Device Identifiers (UDID) to allow advertisers to track users’ habits and preferences. Basically, apps would sell UDIDs to advertisers.
  • UDID was reliant on the actual hardware, which means that it was always attached to a certain device and couldn’t be limited, changed, or reset.
  • This was particularly problematic if UDIDs were get leaked. Hacker group Antisec publicly released 1,000,001 UDIDs in September 2012. In spite of rumours that the UDIDs were found on an FBI computer, app publisher Blue Toad was actually responsible for the breach.
  • Since UDIDs are attached to hardware, nothing could be done to seal the breach. Blue Toad apologized for being hacked, but it refused to notify affected users.
  • After Congress raised privacy concerns about advertisers using UDIDs without permission, Apple banned developers from accessing them in March. Those who didn’t listen were kicked out of the app store.

What’s an IFA?

  • With UDID basically frowned upon by Apple, there was a period of months in which tracking mostly stopped on the iPhone and iPad. Then Apple introduced IFA with the iOS6.
  • According to Apple:
  • Unlike UDIDs, IFA is located in a device’s settings rather than in the hardware.
  • An IFA is a random, non-permanent, and anonymous number (meaning users aren’t personally identified) that can be reset or even turned off — although its default is to be on. It’s kind of like a cookie.
  • While IFA appears less intrusive than the UDID, it also appears to track more habits than before. Decrypted Tech writes, “IFA can track you all the way through to purchase or app download giving advertisers more ammunition to fine tune their ads and targeting algorithms.”
  • According to MoPub, an ad server for mobile apps, IFA will have a positive effect on publishers’ revenues. 
  • Mobile publisher Apsalar makes the point that IFA is better for advertisers by using the example of someone selling his or her phone to someone else. “With the old UDID model, the UDID would stay constant and the new phone owner’s profile data would get mixed in with the former owner’s data.  With the new IDFA, if the original user resets his new phone, he will get a new IDFA and his profile will stay constant without any cross-contamination of profiles.”

Potential problems with “limiting” ad tracking:

  • Most people won’t even know that they have to take action in order to disable tracking. Mobile Theory CEO Scott Swanson told us, “The biggest thing we’re excited about is that it’s on by default, so we expect most people will leave it on.”
  • Even if users take the time to limit tracking (learn how here), their identifiers will still be sent to advertisers. The information, however, is flagged and advertisers should respect users’ wishes.
  • pointed out that this flagging model is similar to Do Not Track on web browsers, “but with some important gaps like Exception management and some definitions around what behaviours are expected by third parties once the user has set the flag.”
  • Apple’s disclaimer (pictured above) says it all: right now advertisers only might not use your information if you limit tracking because “you may still receive targeted ads.” Later, all apps will be required to use IFA.

There’s still a lot to learn about Apple’s tracking policies. We will keep you updated as more information arises.


  • Apple Is Quietly Tracking iPhone Users Again, And It’s Tricky To Opt Out
  • VIDEO: How to disable tracking on your iPhone
  • How To Get Advertisers To Stop Tracking Your iPhone

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