Microsoft Edge received the lowest privacy rating in a recently published study that compared the user information collected by major browsers. Yandex, the less-popular browser developed by the Russian Web search provider Yandex, shared that dubious distinction. Brave, the upstart browser that makes privacy a priority, ranked the highest.
The rankings were revealed in a research paper published by Trinity College Dublin computer scientist Doug Leith. He analyzed and rated the privacy provided by Google Chrome, Mozilla Firefox, Apple Safari, Brave, Edge, and Yandex. Specifically, the study examined the browsers’ sending of data—including unique identifiers and details related to typed URLs—that could be used to track users over time. The findings put the browsers into three categories with Brave getting the highest ranking, Chrome, Firefox, and Safari receiving a medium ranking, and Edge and Yandex lagging behind the rest.
In the paper, Leith wrote:
Strong, Enduring Identifiers
Both Edge and Yandex send identifiers that are tied to device hardware, the study found. These unique strings, which can also link various apps running on the same device, remain the same even after fresh installs of the browsers. Edge sends the universally unique identifier of a device to a Microsoft server located at self.events.data.microsoft.com. This identifier can’t easily be changed or deleted. What’s more, the Edge feature that autocompletes website requests—and in so doing, sends details of typed sites to a backend server—can’t be disabled. The researcher said that he was unaware of any way users could disable the data collection.
This story originally appeared on Ars Technica, a trusted source for technology news, tech policy analysis, reviews, and more. Ars is owned by WIRED’s parent company, Condé Nast.
Yandex, meanwhile, collected a cryptographic hash of the hardware MAC address and details of visited websites through the autocomplete function, although the latter could be disabled. Because Edge and Yandex collect identifiers that are linked to the hardware running the browsers, the data persists across fresh browser installs and can also be used to link various apps running on the same device. These identifiers can then be used to track IP addresses over time.
“Transmission of device identifiers to backend servers is obviously the most worrisome since it is a strong, enduring identifier of a user device that can be regenerated at will, including by other apps (so allowing linking of data across apps from the same manufacturer) and cannot be easily changed or reset by users,” the paper warned.