Implementing anonymous authentication and double voting prevention

Question

I am thinking for ways to implement a mechanism which enables a user to vote,without logging any of his details. Each user has a set of attributes that enable him to vote. For eg. Id,name,email-id.

Using these attributes we must guarantee that the user can vote for the first time. During this time,complete anonymity is guaranteed.

But if the user comes for a second time to vote,he should not be allowed to vote. Is this remotely possible?We are not storing any of the information related to the user.No ip adddress,email-id or student id. They are just used as a means of authentication.

I read many research papers for this but not able to find anything specific.

Answer 1

a mechanism which enables a user to vote,without logging any of his details

Sure you can. Just don't log anything. But you do need to store information about which user has voted. You actually need info of the user not even the machine the user used as the user could vote from another machine.