Apple cracks down device fingerprinting that tracks app users

Apple cracks down on apps that use device fingerprinting to track users


iPhone Device Fingerprinting
Just like you have fingerprints, your iPhone can have a device fingerprint.
Photo: Cult of Mac

Apple warned all App Store developers that it’s starting a crackdown on using device fingerprinting for user tracking.

As a means of preventing this invasive tracking, Apple will soon require devs to justify the inclusion of all APIs in software submitted to the App Store.

Device fingerprinting is forbidden by Apple

Some unethical developers use their apps to collect data about the computers the software is installed on. They’re hoping to build profiles on the devices sufficient to identify them. This is called device fingerprinting. Groups of developers can use these fingerprints to track users as they switch applications.

In a recent post on Apple’s developer site, the company reminded coders that “regardless of whether a user gives your app permission to track, fingerprinting is not allowed.”

Apple’s solution is to require developers to explain the reason for every API (application programming interface) used in their software. This information must go into the app’s privacy manifest file. The goal is to prevent the addition of APIs intended only for fingerprinting.

This requirement is for iOS, iPadOS, tvOS, visionOS and watchOS. And it comes with teeth: “Apps that don’t describe their use of required reason API in their privacy manifest file won’t be accepted by App Store Connect,” Apple warns.

The new rule goes fully into effect in spring 2024.

Tracking is up to users, not developers

Starting in 2021 with the launch of App Tracking Transparency, third-party applications must ask for permission before tracking their users. As Apple says, ”App Tracking Transparency lets you control which apps are allowed to track your activity across other companies’ apps and websites.”

Visit the Settings app to control which apps track you.

Device fingerprinting gives shady devs a potential way to escape the restrictions of App Tracking Transparency. Users have no control over this type of tracking, which is why Apple forbids the practice. Experts predicted that unethical developers would turn to the sneaky tactic as soon as Apple implemented App Tracking Transparency.


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