MetaCaptcha uses the proof-of-work (or “client puzzle”) approach for combating spam. Proof-of-work approaches slow down spammers by requiring them to solve computational puzzles before accessing a desired service. The idea is to impose a per-access cost in hopes of reducing abuse. More specifically, the cost to spammers will be computational resources that they devote to solving a puzzle before sending each message. The approach was first outlined by Dwork and Naor. However, Laurie and Clayton demonstrated that a small constant cost would fail to significantly reduce spam and a large one would burden legitimate users. Later, Liu and Camp demonstrated that if puzzle difficulties were based on user reputations then a proof-of-work approach would indeed be successful. Thus, malicious clients (spammers) would need to be issued “harder” (longer to solve) puzzles than non- malicious clients. The new comments on your blog will be sent to our MetaCAPTCHA server for spam classification.
- Upload folder
- Activate the plugin through the ‘Plugins’ menu in WordPress
- Register an account at http://www.metacaptcha.com/metacaptcha/documentation/registration/ and get the PRIVATE_KEY and PUBLIC_ID. Replace your PRIVATE_KEY and PUBLIC_ID at line 3 and 4 of metacaptcha_lib.php
Contributors & Developers
“MetaCAPTCHA” is open source software. The following people have contributed to this plugin.
- Add useful computation fishy
- Add exchange shared secret key
- Fix readme.txt
- Fix readme.txt
- Simplify the cookies model
- Storing local score and timestamp
- Update code so it can work with MetaCAPTCHA protocol located on rabbit.cs.pdx.edu
- Reload page after verifying cookies complete