We are leaving our digital footprints all over the Internet every day and now we may be leaving our fingerprints as well.
Since the clampdown on cookies tracking a few years ago, the scramble has been on for advertisers to find new ways to track your every move online. They have apparently found a fairly effective one.
It is called “canvas fingerprinting” and like cookies it essentially allows third parties to track the websites you visit and exactly when you visit them. Perhaps most interesting about canvas fingerprinting is the fact it doesn’t actually place files on your PC, finding a nice loophole in the legislation against cookies.
Tech expert Mike Galke, of Spectrum Computing in New York explains how canvas fingerprinting works saying, “Your browser essentially draws a small image on your screen when you visit a website. Certain unique characteristics of your browser and computer mean that this image is drawn in a very unique way that can be used to identify you. That info is then sent back to the server. That data can then be used to create a ‘fingerprint’ of the computer, which could be useful for identifying the computer and serving targeted advertisements.”
As you’d expect, online privacy advocates have been more than a little concerned over the technology.
A team of researchers from the University of California actually began tracking canvas fingerprinting as far back as 2012 and found it to be a very subtle and effective means to silently track the web sites users visit.
“The tracking mechanisms we study are advanced in that they are hard to control, hard to detect and resilient to blocking or removing,” the researchers wrote in a recent white paper on the subject. “Canvas fingerprinting uses the browser’s Canvas API to draw invisible images and extract a persistent, long-term fingerprint without the user’s knowledge.”
Regarding the very sticky issue of online privacy the researchers added, “A frequent argument in online privacy debates is that individuals should take control of their own privacy online [but] our results suggest that even sophisticated users may not be able to do so without significant trade-offs.”
In a recent study done by Princeton University and KU Lueven University in Belgium, researchers there discovered that 5.5 percent of the top 100,000 sites are already using canvas fingerprinting.
Galke adds that there are ways to block canvas fingerprinting using tools such as AdBlockPlus or Blur from Abine, two extensions that can block web trackers. However, his favorite consumer online privacy protector is dubbed Ghostery, a tool used by some former and current U.S. intelligence officials in their private browsing lives. He explains this app simply sits in your browser and canvas fingerprinting won’t work once it’s there.
“The good news is that canvas fingerprinting appears to work best on smaller websites with stable communities,” Galke said. “It hasn’t proven to be accurate enough on a larger scale. However, it’s important for everyone to know that they are being tracked but it’s even more important for them to know they can get back some control of their online privacy too.”