Cookies for different browser

I am using asp.net with c#.

My issu开发者_运维问答e is this that I am setting cookies to check that the same user is returning or not but user are returing from the same machine with different browser. Is their any alternate I would know that same machine user had visited my site.

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Not unless you checked their IP, but then again that's probably worse since multiple computers are usually hiding behind 1 IP.

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The short answer is - NO !!!

If there was a way to track the same user no matter what s/he is using, than browser vendors and protocol specification would be doing an awful job in protecting our privacy :))