With the growth of connectivity to smart grids, new applications, and the changing interaction between customer and energy clouds, clouds are more vulnerable to denial-of-service attacks. Efficient detection methods are required to authenticate, detect and control attackers. Completely Automated Public Turing test to tell Computers and Humans Apart, CAPTCHA, is one efficient tool to thwart denial of service attacks. The server presents the user with a client puzzle to solve in order to gain access to the service or website. The puzzle should be hard enough for computers, but easy for humans to solve. Several methods have been suggested including the popular image-based, as well as video-based, and text-based CAPTCHAs. In this paper, we present a new Flash-based gaming CAPTCHA to differentiate bots from humans. We propose a drag and drop client puzzle where the user will play a simple game to answer a visual question. Our method turns out to be convenient, easy for users and challenging for bots. Additionally, it has gaming aspect, which makes it interesting to users of all age groups.

随着与智能电网，新应用程序的连接性不断增长，以及客户云与能源云之间不断变化的交互作用，云更容易受到拒绝服务攻击。需要有效的检测方法来认证，检测和控制攻击者。完全自动化的公共图灵测试可以告诉计算机和人类，CAPTCHA是阻止拒绝服务攻击的一种有效工具。服务器向用户呈现一个客户难题，以解决该难题，从而获得对服务或网站的访问权限。这个难题对计算机来说应该足够困难，但是对于人类来说却很容易解决。已经提出了几种方法，包括流行的基于图像的，基于视频的和基于文本的CAPTCHA。在本文中，我们提出了一种新的基于Flash的游戏验证码，以区分机器人与人类。我们提出了一个拖放客户端难题，用户将在其中玩一个简单的游戏来回答视觉问题。事实证明，我们的方法非常方便，易于用户使用和对机器人具有挑战性。此外，它还具有游戏方面的功能，这使所有年龄段的用户都对其感兴趣。