Date Added: Aug 2010
Human attestation is a promising technique to suppress unwanted bot traffic in the Internet. With a proof of human existence attached to the message, the receiving ends can verify whether the content is actually drafted by humans. This technique can significantly reduce bot-generated abuse such as spamming, password cracking or even Distributed Denial-of-Service (DDoS) attacks. Unfortunately, existing methods rely on the probabilistic characteristics of attestations and can be exploited by smart attackers.