@article{oai:miyazaki-u.repo.nii.ac.jp:00005901,
 author = {藤, 竜成 and Fuji, Ryusei and 水田, 陸 and Yamaba, Hisaaki and 山場, 久昭 and Aburada, Kentaro and 油田, 健太郎 and Okazaki, Naonobu and 岡崎, 直宣 and 藤, 竜成 and Fuji, Ryusei and Mizuta, Riku},
 journal = {宮崎大学工学部紀要, Memoirs of Faculty of Engineering, University of Miyazaki},
 month = {Jul},
 note = {In recent years, illegal activities such as acquiring a large amount of web service accounts by using an automatic program called a bot have been problems. In order to prevent such activities, a discrimination method based on the Turing test for identifying a human and a bot called CAPTCHA was developed. Also, mobile devices such as smartphones have appeared and are often used to access web services. However, many of the existing CAPTCHA methods can't be adapted well to mobile devices, which is a cause of the decline in the success rate of the account registration of the web service. Therefore, it is necessary to design a CAPTCHA which is easy to use in mobile devices. In this paper, we propose a new CAPTCHA scheme that maintains convenience in mobile devices and has bot tolerance. In proposed method, several objects move randomly and continuously. One of the objects selected by the user from among several objects is set as a tracking target. According to the time that the users can track the target with their finger, the proposed system determines whether the users are humans or bots. In our proposed method, the transparency of color and the degree of change of transparency for each object are set at random, and by changing the transparency of the object as time proceeds, the method can withstand the bots that perform fraudulent activities using object tracking technology.},
 pages = {257--262},
 title = {モバイル端末向けの動的CAPTCHAの検討と追跡技術を用いたボット耐性の検証},
 volume = {48},
 year = {2019},
 yomi = {フジ, リュウセイ and ミズタ, リク and ヤマバ, ヒサアキ and アブラダ, ケンタロウ and オカザキ, ナオノブ and フジ, リュウセイ}
}