I have a question that may sound a bit dumb, but still ... And yes, this post does belong to the "security" section since i need this info to implement some more security functionality to my site. how do the websites identify visitors besides the IP ? A perfect example is the banking websites (BOFA, for example) which say "we don't recognize your computer" as soon as you use a different computer and try to log in. The mystery part for me is that i connect a new computer to the SAME ip as my old computer and it still does not recognize the new computer - which means it doesnt have to do with the IP Or, another counter-example, is that when i use the same notebook from different IP, the site behaves normal and recognizes me just fine. So, it somehow does detect the computer itself, not the IP... Please teach me how do they do it ? What's that key identifier of a computer ? is it browser's version ? is it browser's setting ? is it the computer's name (the one that you set when installing windows)? or is it something else that i didn't think of ?? Thanks
It will be a simple cookie, or if you've downloaded anything from the bank to allow the functionality it may also be recognizing the MAC address. Very simple to implement but no method is fool-proof. IPs may identify a single computer, but if they are connecting via an ISP it will more likely be an ever changing group of users who share the same IP of the ISP's router. Cookies will identify an individual computer but not who is using it at the time unless a log-in system is used, but then it will only identify the logged-in user on that computer which may be a different individual if that other individual knows the login details.
forgot to say, my cookies are being wiped every time i close the browser. So in this case it is not cookies too ...
In that case you must have downloaded something from the site or else you installed something from a DVD or CD provided by that company. It may have been an activeX control (Windows) or some other small programme. It's the only way this could be done short of your computer being compromized and the programme installed without your knowledge - which them has some ethical issues attached to it.