iOS 8 Update: A Privacy Win for the Location Data Ecosystem

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At their developer conference during the first week of June, Apple announced many changes coming in iOS 8. One of the changes regarded how a device’s MAC address is communicated to WiFi access points.

PlaceIQ doesn’t use MAC addresses to identify devices, and we welcome this change because it protects consumers and reduces potential privacy risks. As it currently stands, MAC address tracking via WiFi is not an opt-in experience and cannot be opted out from.

If you’d like to understand more, including how this works, whom it affects, and why PlaceIQ welcomes the change, read on. Fair warning: it might get a bit nerdy.

So What’s a MAC Address?

A MAC address is a hardware-based identification number, provided by any device that connects to a network. Hardware-based identifiers are read-only, meaning they can never be changed. They are written to the physical network chip in each device. When a device connects to a router or WiFi network, the device is identified by its MAC address for the duration of its connection. This allows the right traffic to be sent to and from your phone, PC, or TV regardless of how many devices are connected.

When your device is in your pocket or purse, it is regularly looking for a known WiFi network to join. This way, when you pull out your phone at home or at work it’s already connected and ready to go. But as your phone searches for WiFi, it is broadcasting its MAC address to WiFi access points within range. It’s part of the handshake devices engage in to recognize each other.

Recently, a few companies have developed WiFi hubs that remember the MAC addresses they see. They log your device as it scans for a hub, whether or not you join the WiFi access point. These companies have installed these logging WiFi hubs in many places, allowing them to compare visitors as they move from place to place, without their knowledge.

Even if people were informed that their devices were being monitored, the only way to prevent this type of tracking is to turn off WiFi completely. That’s a rather extreme step.

Finally, there’s a difficulty with hardware-based identifiers. The mobile advertising industry, including big players like Google and Apple, has worked hard to move away from hardware-based identifiers as much as possible. Software-based identifiers, like Apple’s IDFA, can be reset by users or blocked entirely. Hardware identifiers will not change for the life of the device. If there is a data leak and a malicious source obtains a hardware-based device identifier, the only way to ensure you will not be affected is to buy a new device.

A Privacy Challenge

So Apple was faced with a challenge: their users’ devices were being logged without their knowledge, without their consent, all while using a hardware-based identifier. Apple’s adherence to standard network practices – broadcasting MAC addresses to WiFi hubs – created an environment where this situation could occur. So Apple made moves to change that standard practice.

Starting in iOS 8, iPhones, iPads, and iPod Touches will broadcast random MAC addresses. In Apple’s words, “The MAC address for WiFi scans may not always be the device’s (universal) address.” Companies that log MAC addresses won’t be able to connect individual visits to a single device. They’ll know someone is there, but not where else they’ve gone.

Some have suggested that this move is a play to get more people using Apple’s own iBeacon API. This may be true. But iBeacons are much more user friendly. To see a company’s iBeacons, users must install an associated application and grant it the appropriate location permissions. Applications that use iBeacons are opt-in and users are always able to opt-out by managing their location permissions in their device settings.

The Right Move

iOS has a history of protecting user privacy and providing access controls. In fact, this isn’t their first big MAC address change. Last year they blocked applications from accessing the MAC address. And this wasn’t their only update to location privacy this year: with iOS 8, Apple is introducing much more explicit background location access controls.

Overall, I believe Apple’s decision to randomize MAC addresses is a win both for users and the location data ecosystem. They provide a managed space where developers can innovate without overstepping user expectations.

As a growing number of applications use location in more diverse ways than ever before, they can now do so in an environment where users still retain control.