http://gpvdip7rd7bdy5gf7scl3rzgzgzckqw4sqxbmy6g3zijfwu4lz3ypbyd.onion/Personal/blogs/http_fp_en.html
CSS will only apply style rules when the browser supports a certain CSS feature (otherwise ignored ). Also some rules can send a request with url(). Combining them you can more or less detect which CSS features are supported, or enabled (Including fonts, window size). As an example : magic-query .css_probe_42 {background: url('/signal/(token)/(signalName)') ;} Then there is TLS fingerprinting too, based on parameters, extensions between the different TLS libraries used by...