摘要：Beginning around 1996, numerous graphical password schemes have been proposed, motivated by improving password usability and security, two key factors in password scheme evaluation. In this paper, we focus on the security aspects of existing graphical password schemes, which not only gives a simple introduction of attack methods but also intends to provide an in-depth analysis with specific schemes. The paper first categorizes existing graphical password schemes into four kinds according to the authentication style and provides a comprehensive introduction and analysis for each scheme, highlighting security aspects. Then we review the known attack methods, categorize them into two kinds, and summarize the security reported in some user studies of those schemes. Finally, some suggestions are given for future research.
