I'm trying to add a rating system to my image gallery. I know how to make the web form and do the calculations to see how many stars out of five its earned. The problem is, all the images are being loaded from the same hash. I want it to be setup where you can vote on any images you want, but you can NOT vote on the same image twice.
The method? IP blocking, I don't see any other way to do it. But I can't setup one big .txt will IPs that already casted a vote on an image because that would block them from voting on other images as well.
Any suggestions on how to go about doing this?