New Study Points Fingers at Apple’s “Differential Privacy”

BY Chethan Rao

Published 18 Sep 2017

iOS Security

A recent study collectively posted by five researchers from the University of Southern California, Indiana University, and Tsinghua University, China has suggested that Apple’s “differential privacy” collects more user data than originally claimed. This method is used by Apple to gather information on device usage, diagnostics and more, with some user data present as well.

Apple initially claimed that this method adds a lot of noise to ensure the safety of the user data and so that the company can only obtain non-specific information they require.

This study, however, suggests that Apple’s method allows for more specific data to pass through the buffers than claimed by Apple. The company uses differential privacy on macOS and iOS, although the researchers have found there to be a lot more issues with iOS with regards to the seeding of specific data.

The research has also found that Apple keeps its data loss parameters, otherwise known as “epsilon”, a secret. This basically allows Apple to change it up internally without much information to the outside world.

Researchers have concluded that Apple’s epsilon rating is higher than normal, and pales in comparison to Google’s epsilon ratings with products like Chrome. Google makes its code available on open source platforms, which allows researchers and developers to double check its claims. Apple doesn’t have such a system in place.

To put things in perspective, Apple’s iOS 10 is believed to have an epsilon rating of 14, while macOS apparently has a rating of 6. Chrome, however, doesn’t usually exceed 2, with a lifetime ceiling of 8 to 9. Strangely enough, Apple’s iOS 11 beta was said to have an epsilon of 43. But this shouldn’t be a concern as data gathering on a beta operating system is imperative to squash any bugs before the big release. iOS 11 will officially hit existing iOS devices on September 19.

Apple, in response to this research, has mentioned that most of its data is opt-in and collected as part of the usage and diagnostics information. Users get a prompt when they set up their iOS device seeking permission to gather information. Keeping this in mind, Apple believes that it cannot correlate a data with a specific person given the fact that it’s opt-in, and also due to the kind of buffers it uses.

[Via Wired]