Classifying the Security Level of User Authentication for Secure Computing

In order to provide more suitable user authentication services for secure computing environments, we classify the level of the user authentication into three security levels. As the security level of user authentication is classified, not only the legacy schemes can be used properly, but also the improved schemes will be introduced for more efficient secure services. In addition to this work, we also propose the improved user authentication schemes using either public key certificate or self-certified public key. At last, these schemes will be reasonable to provide the secure services for secure computing environments.