An image-based user authentication that is easy to remember, difficult to forget, and robust against observing attack

基于图像的用户认证是有效的，因为人类对先前看到的图像的识别比对密码的精确回忆要有效得多。然而，图像的使用导致对观察攻击的脆弱性。为了科普这些问题，我们提出了一个用户认证使用“不清晰的图像”作为通过图像。即使对人类来说，也很难记住一个毫无意义的图像。这就是为什么预期未授权用户难以记住授权用户的不清楚通行证图像的原因。在注册阶段，只有授权用户才能看到与其不清晰的通过图像对应的原始图像。授权用户通过看到原始图像，可以识别不清楚的通行证图像中的含义，并且可以通过使用原始图像作为线索来容易地记忆和记住它们。这种线索在认知心理学中被称为“图式”。在本研究期间，我们尝试从对观察攻击的鲁棒性、诱饵图像的自动生成以及增强其可用性等方面对基于不清晰图像的用户认证进行改进。

The image-based user authentication is effective since humans are significantly more efficient about recognition of previously seen images than precise recall of passwords. However, the use of images results in vulnerability against the observing attacks. To cope with these issues, we propose a user authentication using “unclear images” as pass-images. Even for humans it is hard to remember a meaningless image. That is why it is expected to be difficult for unauthorized users to memorize authorized user’s unclear pass-image. Only the authorized users are allowed to see the original images corresponding to their unclear pass-images in the enrollment phase. By seeing the original images, the authorized users can recognize the meaning in the unclear pass-images and can easily memorize and remember them by using the original images as a clue. This kind of clue is called as “schema” in cognitive psychology. In this research period, we tried to improve the unclear-images-based user authentication from the aspect of from the robustness against observing attack, automatic generation of the decoy images, and the enhancement of its usability.