@article{oai:miyazaki-u.repo.nii.ac.jp:00005241,
 author = {日隈, 光基 and Hinokuma, Koki and Yamaba, Hisaaki and 山場, 久昭 and 久保田, 真一郎 and Kubota, Shin-Ichiro and Okazaki, Naonobu and 岡崎, 直宣 and 日隈, 光基 and Hinokuma, Koki and 久保田, 真一郎 and Kubota, Shin-Ichiro},
 journal = {宮崎大学工学部紀要, Memoirs of Faculty of Engineering, University of Miyazaki},
 month = {Jul},
 note = {Currently, user authentication methods such as PINs, passwords and so on, are used to protect important and private data in mobile devices. However, those existing methods are not sufficiently safe against shoulder surfing attacks. Attackers can easily steal PIN codes or passwords. To prevent such attacks, the puzzle authentication method was proposed. In the method, users unlock their devices thorough solving a “puzzle." A user drags an orb to adjacent positions, and the dragged orb swaps places with the orb already there. The authentication will succeed when all of the orbs corresponding to characters of the password are put into the designated positions. The special feature of this method is that users have fun while they unlock their devices. However, it was also known that the method has several drawbacks. First, the method is not strong enough against brute-force attacks. Next, the correct answer is easily revealed by shooting the authenticated screen using a video camera. In this study, several improvements were made to the method to overcome brute-force attacks and video recording attacks. The improved authentication method was implemented and experiments for evaluation were carried out.},
 pages = {263--268},
 title = {録画画像を用いた攻撃に耐性を持つパズル型認証方式の提案},
 volume = {46},
 year = {2017},
 yomi = {ヒノクマ, コウキ and ヤマバ, ヒサアキ and クボタ, シンイチロウ and オカザキ, ナオノブ and ヒノクマ, コウキ and クボタ, シンイチロウ}
}