Yes, it’s true.  With a few relatively simple programming tricks, a web site can effectively discern your browsing history.  Any web site, if they so desire, can figure out quite a lot of information about where you have been on the Internet as well as what you have searched for on well known search engines.

How:  Most people who surf the net have their browsers set to remember several weeks of browsing history, and they could visit a lot of web sites over that period of time. 

Well, unbeknownst to you, you may be letting on a lot more than you realize.

Cookies can also be used to spy on your browsing habits, but this techmique has nothing to do with cookies.  Therefore even if you diligently delete cookies, you may falsely believe your browsing habits will not be passed on to some other site you visit. 

How is this done?  All it takes is a simple bit of CSS and/or JavaScript code, and a database of links to test.  They can test up to a million links per minute.  That is right, I said a million links per minute.  And you won’t have a clue it is going on.

Now, what do you suppose a web site would want to test for?   Huh?  Just use a little imagination and you will answer that question for yourself.

The results can be added to another database that includes your I.P. address and whatever other identifying info can be gleaned from cookies and standard data that all browsers give out.  This standard data includes the brand of browser you are using, screen resolution and enough other information to uniquely identify your computer with a high degree of accuracy.  And that is not all.  Other techniques can test for content in your browsers cache.

 How to combat this?  Some suggestions:

• The most reliable way is to set your browser to not keep a browsing history (or to keep a very minimal history, say a day or two), and delete the history you already have.  
• Set your browser so that new and visited links have the exact same color.
• Keep your cache relatively small and delete it regularly, if not for every session. 
• Surf with a variety of browsers.

For more info, and to test your browser, you may visit the following links:

 http://www.whattheinternetknowsaboutyou.com

 http://startpanic.com/

Remember: Practice Safe Computing!

Posted on Saturday, April 10th, 2010 at 11:48 PM and filed under Exploits, General, Online Security, Privacy. You can follow any responses to this post through the RSS 2.0 feed. You can leave a comment, or you may trackback from your own site.