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<p class="MsoNormal" style="text-align: left; margin: 0cm 0cm 0pt;" align="left"><span class="text"><span style="font-family: ";Arial";,";sans-serif";; font-size: 9pt;">As the ubiquitous society spreads rapidly, various private information circulates in large quantities. Information increases explosively in recent years, the importance of privacy protection has risen. When the Web services are used, they need not identify who is the user in some cases. In this paper, we propose the authentication method that achieves privacy protection with authorization without identification. Our method makes it possible to protect user’s privacy information when the services. We discuss the security of the attacks, and the untraceability from attribute information to identity information. Thereby we show the effectiveness of our method.</span></span><span style="font-family: ";Arial";,";sans-serif";; font-size: 9pt;"></span></p>

We propose a method for managing online accounts from the point of view of risk management. The proposed method reduces the risk of a personal information leakage, while permitting users to reuse passwords. We further propose a way to measure the risk of personal information leakage in order to estimate the risk impact. This proposed risk value is an index of the quantitative influence of leaked personal information. We evaluated the ability of the proposed method to minimize the risk of personal information leakage and the number of passwords that users can remember. In this evaluation, the α-group contained five passwords, and the β-group contains seven passwords. Thus, we conclude that the proposed method is useful as a whole.

No abstract

Single sign-on (SSO) is an identity management technique that provides the ability to use multiple Web services with one set of credentials. However, when the authentication server is down or unavailable, users cannot access these Web services, regardless of whether they are operating normally. Therefore, it is important to enable continuous use alongside SSO. In this paper, we present an identity continuance method for SSO. First, we explain four such continuance methods and identify their limitations and problems. Second, we propose a new solution based on an identifier migration approach that meets the requirement for identity continuance. Finally, we discuss these methods from the viewpoint of continuity, security, efficiency, and feasibility