Plugin for Election of a Board of Directors

[elffuts]

I need a plugin that will handle the annual election of a Board of Directors for a 300-member organization. It should be able to handle two candidates for each office, up to 10 offices, and a write-in option for each office. It should limit each member to voting only once for each office, should keep each member’s vote confidential, and should be secure in the sense that non-members are prevented from voting. Results should not be available until after the election is over. I’ve searched for several hours and found nothing. Can anyone please direct me toward a solution?