Abstract or Summary:
Single sign-on (SSO) is a mechanism whereby a single action of user authentication enables a user to access web services without entering multiple passwords. But, the SSO is not used much now, because almost all portal sites become Identity Providers (IdPs) and we have to use too many IdPs. That is, it is no longer a "single" sign-on. In this paper, we propose an SSO using a very personal portable IdP that we can carry on a USB flash drive.