Abstract
In this paper we propose the concept of Certificate-free Attribute Authentication (C-AA), which holds a few interesting features, such as a user can demonstrate (1) he owns sufficient attributes to pass an attribute verification without showing his full attribute details, (2) he has been authorized by a number of authorities without revealing his identity, and (3) no certification of the user's public key is required, and his secret key as a whole is not escrowed by any authority. Although these features have individually been used in various of cryptographic primitives, in this paper we combine them together and demonstrate a Certificate-free Attribute Authentication Scheme (C-AAS) is useful in practice. We provide a formal definition of a C-AAS and four security notions: full anonymity, full traceability, non-frameability and attribute unforgeability. We also construct a concrete C-AAS and prove it is correct and secure under the definition and security notions.