Efficient and Secure Attribute-Based Signatures for General Circuits

Attribute-based signature is an important cryptographic primitive and has attracted the attention of many scholars. Because of its good properties, attribute-based signature has found significant applications in many fields, such as message delivery, anonymous authentication, leaking secrets, trust negotiations, private access control, anonymous credentials, etc. To improve the security, expressiveness, and efficiency of attribute-based signature, an efficient and secure attribute-based signature scheme with perfect privacy for general circuits is proposed by using multi-linear mapping. By introducing the concept of node weight and adopting the "top-down" recursive, the computation cost of signature generation is reduced. The sizes of the keys of the gate nodes are reduced by using the symmetry of the left and right child nodes. Compared with the previous scheme, the proposed scheme improves the unforgeability from "existential unforgeable under selective message and selective attribute attack" to "existential unforgeable under adaptive chosen message but selective attribute attack." The proposed scheme extends the access structure from special circuits to general circuits, which can support arbitrary access structures and achieve arbitrary access control granularity. The proposed scheme keeps the signature as only one group element, shortens the sizes of the master public key, master private key, and signing key markedly, and reduces the computation overheads of signing key generation, signature generation, and signature verification significantly. The analysis shows that the proposed scheme has obvious advantages in performance and efficiency and is practical.