Tracking post votes from guests

I'm currently working on a site that implements a voting system for posts. It's a completely custom site, no 3rd party software is being used.

I'm trying to track votes from guests. I don't want to require users to register/log in to vote. Mainly because I don't think people would want to create an account JUST so they can vote.

I'm looking for some suggestions for methods to keep users from voting more than once for each post. Tracking VIA IP isn't reliable, so I'm steering away from that. Currently I'm tracking the votes VIA the session... but of course once the session ends, the user will be able to vote again. I've also thought about cookies, but I'm not sure that's the best approach either.

I've seen many -- large -- sites that allow guests to vote. How do they prevent voter fraud from guests?

Any fresh ideas?

 

Do it via IP, but also add a captca to prevent auto multi-vote scripts with proxies.

 

The problem with tracking by ip is a: ips change and b: people on home or corporate networks share the same IP. Captchas are generally unfriendly and I try to avoid them. Not to mention there are scripts that can overcome them.

 

I am the principle developer for an online short film festival site. We recently added the ability for guests to vote on entries but because its hard to be reliable when they aren't registering an account we chose to use their votes differently.

The members who register and are an active member of our community are allowed to vote and their votes count toward the main prize categories. The guest vote we use for the Audience Favorite category and also as a secondary set of statistics for us as to how many people are actually visiting/participating.

I know not the answer you were looking for, but maybe a different way of looking at it that might help you.

 

How are you managing votes for guests? I'm not looking for a "one size fits all" solution. I'd really like to discuss some alternate methods.

 

Tough one. The only true secure way is to force registration. Otherwise cookies are the only way to "restrict". You could temporarily limit per IP address but AOL Proxies are still common and so are huge campus networks with SHARED and DYNAMIC IPs. If you are looking to trap quick votes you're going to have to sacrifice accuracy and security...otherwise force registration per unique email AND use cookies.