Implementation of 3-layer image captchas to avoid detect tremendous attacks

The mainstay of this paper is to avoid tremendous attack from malicious computer programs using 3-D static CAPTCHA (Completely Automated Public Turing test to tell Computers and Human Apart) mechanism has been introduced to distinguish humans and computers. Though there are many different kinds of specific implementations for CAPTCHA. It requires users to identify images. Up to now, except some research sites, commercial sites rarely use it. Specific implementation algorithms are: CAPTCHA algorithm based on real object image identification and CAPTCHA algorithm based on image similarity judgment. Draw backs of 2D:Due to the fast development of pattern recognition and artificial intelligence technology, there are increasing safety loopholes concerning traditional 2D static CAPTCHAs, resulting in that certain malicious computer programs could launch serious program attack through breaking such CAPTCHAs. The authors, in this paper propose 3-D Dynamic CAPTCHA algorithm which is not only extremely hard to crack for computer programs using multiple frames, but also easy for humans to identify.