Three stealthy tracking mechanisms designed to avoid weaknesses in browser cookies pose potential privacy risks to Internet users, a new research paper has concluded.
The methods—known as canvas fingerprinting, evercookies and cookie syncing—are in use across a range of popular websites. The findings, first reported by Pro Publica, show how such tracking is important for targeted advertising but that the privacy risks may be unknown to all but the most sophisticated web users.
Profiling Web users, such as knowing what Web pages a person has visited before, is a central component of targeted advertising, which matches advertisements with topics a person may be interested in. It is key to charging higher rates for advertisements.
Cookies, or data files stored by a browser, have long been used for tracking, but cookies can be easily blocked or deleted, which diminishes their usefulness.
The methods studied by the researchers are designed to enable more persistent tracking but raise questions over whether people are aware of how much data is being collected.
The researchers, from KU Lueven in Belgium and Princeton University, wrote in their paper that they hope the findings will lead to better defenses and increased accountability “for companies deploying exotic tracking techniques.”
“The tracking mechanisms we study are advanced in that they are hard to control, hard to detect and resilient to blocking or removing,” they wrote.
Although the tracking methods have been known about for some time, the researchers showed how the methods are increasingly being used on top-tier, highly trafficked websites.