Research On Attribute-Based Signature From Multilinear Mapping

Attribute-based signature(ABS)is a cryptographic primitive with a fine-grained control mechanism and strong privacy.Recently,it has been widely concerned.However,the high computation cost and low efficiency are the major disadvantages of the ABS,which can not meet some application scenarios that require high real-time performance or have limited computing power.At present,there are two ways of thinking in academic circles.The first is to optimize algorithms,but the effect is limited.The second is to outsource the expensive part of the calculation to a third party.Multilinear maps are the generalization and extension of bilinear pairings,which are powerful in the construction of attribute-based cryptography.And multilinear maps support arbitrary boolean circuit structures.This paper uses multilinear maps as a tool to study attributebased signatures and makes progress in algorithm optimization and signature outsourcing.The main contributions are as follows:(1)To solve the security and computational overhead of Tang et al.'s scheme,we propose a more efficient and secure ABS scheme from multilinear mapping,which supports expressive policy.Compared with Tang et al.' scheme,on average,the size of the public parameters and the master secret key of our scheme are reduced to about 12.55%,the size of the private key and the time cost of private key generation 78.56%,the time cost of signing,and verifying is reduced to about 37.84%,and 12.86%,respectively.(2)We propose the concept of "perfect privacy" of outsourced attribute-based signature,which overcomes the disadvantage that the traditional concept of "privacy" does not consider to prevent the signing-cloud service provider from attacking the privacy.And multilinear maps are used to construct an outsourced attribute-based signature scheme that can achieve perfect privacy.