防止投票垃圾邮件的最佳方法是什么？ 即reddit是如何做到的[关闭]

Question

Reddit, as we all know, allows around 1 vote per ip address per link to avoid issues with spammers. I am working on a Slim application that will have a voting feature and I, quite frankly, have no idea how to implement system like this as I have no experience with cookies and native sessions. Also most of my functions have paths like (example) localhost:8888/myapp/voteup/item-to-vote.

Answer 1

On my site I allow members to rate some code between 1 and 5 once every 24 hours. I stop spam by adding a hash code and using ajax to submit a vote. I haven't gotten any spam votes since I added it in June 2012. I used to get about 40 votes per day from bots, but now that has been eliminated for now.

For example this is what my link looks like:
http://phpsnips.com/process/vote.php?id=43&vote=3&enc=a560e4320af4e13e4170947cd42de18b

With that, enc is different every time the page loads, and once the vote is submitted it is changed again.

My steps

• Use a session to create an md5 hash
• place the hash on the link or form hidden field
• On the submission page test to make sure the session matches the link/field
• Reset the hash
• Redirect back to the original page (if not using ajax)