Research Of Efficient Attribute-based Signature Schemes

Digital signature is the main technology used to protect the integrity and non-repudiation of messages in the field of digital communications.As an extension of identity-based cryptography,attribute-based cryptography replaces the specific identity of users with a set of attributes,in this way it achieves the one-to-many fine-grained access control mechanism,while protecting the specific identity information about users.The primitive of Attribute-based Signature(ABS)inherits the above-mentioned advantages simultaneously.Specifically,a signer acquires the signing key according to the signing predicate or his attribute set.However,in the practical scenario,the traditional model of single-authority ABS is trouble to counteract the frequently signing key distribution requests from users,and it overly relies on the only attribute authority,which result in the potential problem of congestion and single point failure.In addition,there exists pairing and many exponential operations in signing and verification algorithms in a ABS scheme.For resource-constrained devices in the network,it requires heavy computational overhead for these devices to perform pairing and exponential calculations.Thus,it cannot satisfy the requirement of practicability.The primitive of multi-authority and server-aided computation provides a novel idea for solving the problem.In order to solve the above-mentioned problems,we implemented detailed research on multi-authority ABS and server-aided ABS to improve the efficiency of ABS system,and obtained the research results as follows:1).This thesis proposes a multi-authority attribute-based signcryption(MA-ABSC)scheme,and then gives the proof of correctness,confidentiality and unforgeability.Besides,this thesis compares the MA-ABSC scheme with several relevant schemes in terms of function and performance.It demonstrates that the proposed MA-ABSC scheme not only equipped with the advantage of multi-authority,but also performs better in signcryption and unsigncryption algorithms.Finally,it demonstrates the practicability of MA-ABSC by means of the experimental simulation.2).This thesis also estimates the security vulnerability of Cui et al.'s SA-ABSR scheme,and then analyzes the essential reason of the security vulnerability..Next,this thesis presents a server-aided attribute-based signature(SA-ABS)scheme with LSSS access policy,then it proves the correctness and existential unforgeability of SA-ABSscheme.Furthermore,this thesis compares and analyzes the SA-ABS scheme with several other server-aided signature scheme with respect to functional property,storage costs and computational overheads.It illustrates the SA-ABS scheme is the first server-aided ABS scheme which delegates computations in signing and verification phases to a server simultaneously,and it also shows the advantage in terms of computational overheads in signing and verification algorithms.Finally,it performs the experimental simulation based on a lightweight mobile device,which used to examine the practicability of SA-ABS scheme in resource-constrained devices.