



The technique has been successfully tested on Chrome 90 (Windows 10, macOS Big Sur), Firefox 88.0.1 (Ubuntu 20.04, Windows 10, macOS Big Sur), Safari 14.1 (macOS Big Sur), Tor Browser 10.0.16 (Ubuntu 20.04, Windows 10, macOS Big Sur), Brave 1.24.84 (Windows 10, macOS Big Sur), Yandex Browser 21.3.0 (Windows 10, macOS Big Sur), and Microsoft Edge 90 (Windows 10, macOS Big Sur). The fact that the identifier remains consistent across different browsers means that cross-browser tracking is possible, which violates privacy expectations. The script uses each app result as a bit to calculate the identifier. It then displays the icon of the requested app if found, and moves on to its next query. But in this case, the demo script just cancels if the app is present or reads the error as confirmation of the app's absence.
