Published 19 years 1 month ago • Last updated March 22, 2025 • ⏱️ < 1 min read
I've been experimenting with the various ways of tracking a user without cookies or sessions and I came up with a unique way of doing so that I haven't really seen documented anywhere. Using the script below you should receive a unique session id; if you then try the script in another browser it should return the same session id.
It works by getting the first digits of your IP address e.g. 192 then combines it with the first 2 digits of your remote port between the server and client, it creates a unique hash from that information. This method would only work within the same session and it would not be possible to track users across new connections.
After discussing this further on the GeekUp mailing list Alan Burlison pointed out that various configurations of servers and load balancers would complicate the remote port assignment so it wouldn't be possible to track a user reliably using remote ports. He also provided a few links on Pipeline HTTP and various specifications of the HTTP standard which I found interesting.
http://tools.ietf.org/html/rfc2616 http://en.wikipedia.org/wiki/Pipelined_HTTP http://en.wikipedia.org/wiki/HTTP_persistent_connection http://httpd.apache.org/docs/2.2/mod/core.html#keepalive http://www.mozilla.org/projects/netlib/http/pipelining-faq.html http://egonitron.com/2007/05/25/the-truth-about-the-firefox-pipelining-trick/