在我們這個資訊時代裡，網路服務已成為相當重要且不可或缺的科技。當越
來越多人使用時，此服務的價值也會提升。但相對的，也更容易成為有心人士攻
擊的目標。為了自身的利益，這些人會試著編寫程式去偷取網路上的資料，或是
濫用現存的許多網路服務，造成許多人的不便。而CAPTCHA 成立就是在預防此
一現象，用來區別人類與機器人。目前CAPTCHA 的開發已超過十年。從早期且
廣泛應用的文字型態，到許多圖形型態的CAPTCHA，應有盡有。但也隨著攻擊
者技術的進步，這些CAPTCHA 也開始逐一破解。
　　由於目前開發環境已獲得大量的改良，3D CAPTCHA 的開發已成為一
種可能性。本篇論文也是提出一套3D CAPTCHA。雖然3D 型態的圖形要呈現
於平面上，會造成許多資訊與面向的損失。不過我們也使用了互動機制來改良
此一問題。除此之外，我們也嘗試去融合商業價值，讓CAPTCHA 的存在可以
協助公司的營利。如此一來，3D CAPTCHA 除了不會損失資訊外，也可以讓
CAPTCHA 增加另一種存在的意義。我們也希望能藉此一架構，開創出另一個
CAPTCHA 的型態發展。

In our digital age, the web services are becoming an important and essential
technology. When more and more people are using it, the value will be raised.
Meanwhile, it is easy to be the target for some attackers. For their own benefit,
these attackers try to write some programs to steal some data on the internet, or
abuse the existing services to cause others’inconvenience. CAPTCHA is created
to prevent against this situation. It is used to distinguish the human from the
programs. CAPTCHA has been developing for more than ten years. There are a lot
of types from the traditional and wide-spreading text-based CAPTCHA, to some
other image-base ones. But as the techniques of attackers are getting improved,
these CAPTCHAs are beginning to be broken.
Due to the developing environment is largely improved, 3D CAPTCHA now is
becoming possible. This essay is to propose a 3D CAPTCHA. The image of 3D
is presented on the 2D screen and it might cause the loss of the information and
views, but we utilize the interactive mechanism to solve this problem. Besides, we
also try to combine the commercial value, which helps the CAPTCHA assist the
income of the company. Therefore, 3D CAPTCHA will not only cause the loss
of information, but also increase the meaning of CAPTCHA. We hope this could
inspire other people to develop another new CAPTCHA based on our scheme.

1 Introduction
2 Background
3 Related Works
4 Proposed Scheme Method
5 Implementation
6 Experiments and Analysis
7 Conclusion

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