Ways to create a unique user fingerprint in PHP

php statistics user-agent identifier fingerprint
So Over It picture So Over It · Nov 3, 2010 · Viewed 49.7k times · Source

What is the best way to generate a 'fingerprint' of user unique-ness in PHP?

For example:

  1. I could use a user's IP address as the 'fingerprint', however, there could be multiple other users on the same IP
  2. I could use the user's IP + user agent as the 'fingerprint', however, a single user could simply swap from safari to firefox and again be seen as being unique

Ideally, the fingerprint so label the 'machine' rather than browser or 'ip' but I can't think of how this is achievable.

Open to ideas/suggestions of how you uniquely identify your users, and what advantages/disadvantages your method has.

Answer

JAL picture JAL · Nov 3, 2010

This site covers pretty much every piece of information you can use to distinguish individuals through a browser.

https://panopticlick.eff.org/

JavaScript, Java and Flash help a lot.

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