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phpajaxvotingvoting-system

Best method to prevent gaming with anonymous voting

I am about to write a voting method for my site. I want a method to stop people voting for the same thing twice. So far my thoughts have been:

  • Drop a cookie once the vote is complete (susceptible to multi browser gaming)
  • Log IP address per vote (this will fail in proxy / corporate environments)
  • Force logins

My site is not account based as such, although it aggregates Twitter data, so there is scope for using Twitter OAuth as a means of identification.

What existing systems exist and how do they do this?

Solution

  • The best thing would be to disallow anonymous voting. If the user is forced to log in you can save the userid with each vote and make sure that he/she only votes once.

    The cookie approach is very fragile since cookies can be deleted easily. The IP address approach has the shortcoming you yourself describe.