There is a site with various questionnaires on php.
It is necessary to make protection against cheating votes. The site should be provided with the functions: 1. "To plant one by one for one computer of people and pass for each survey". That is the filter one poll-one ip will not work. 2. Paste a poll widget on any site.
What thoughts are there:
Generate token on the server. Give to the page and when sending the results to compare and update token. This will help to avoid auto queries on the URL with the results, for example, from fiddler. (or will not help?)
Make it impossible for one ip to vote more than once every 10 seconds (or another time interval)
Or make it possible to vote with one ip administrators only (for example)
PS About 1. option. token is saved per session. The poll widget is inserted via iframe. But in the iframe session is not saved - how to be?