In real life, many attributes of a user are monitored by a single authority, which will inevitably increase its workload and reduce its efficiency. In this paper, the proposed multi-authority Attribute-based Signature scheme is that many attributes are monitored by many different authorities respectively, and in addition, a credible central authority is required to manage and constraint these authorities ,then a new signature scheme is constructed and by using the methodology of reductionist security argument its security is proved equal to discrete logarithm problem and computational Diffie-Hellman problem . This scheme has some advantages, such as protecting the private information of a user, and a higher efficiency in signature.
