voting security

[iamalem]

I have designed an electronic voting page but it does not prevent the voter from voting more than once by simply clicking the 'back' button and voting again. What should i do to prevent the vote casting page from being displayed after a vote has been casted?

[Old_Geezer]

You could use a cookie to inform your site that they have been here before. But they can delete those.

Or you could keep a database of all the millions of addresses that have already voting and check it each time.

[rojash]

"Or you could keep a database of all the millions of addresses that have already voting and check it each time. "
...but they could change those by resetting their routers.