Aggregate Signature And Aggregate Signcryption And Their Application Research

With the rapid development of information technology,people can transmit all kinds of information through network technology in the big data era.However,data privacy leakage occurs frequently.For people,the biggest concern and demand is the security of information.Fortunately,cryptography technologies can achieve secure communication.Encryption can achieve the confidentiality of information,it is keeping information secret from all other than those who are authorized to see it.Signature can achieve the authentication,integrity and non-repudiation.Later,in order to solve the problem of low efficiency and heavy workload when verifying the signatures alone,Boneh proposed the idea of aggregate signature in 2003.Through batch verification,i.e.,the signatures from different users are aggregated into a short signature,the verifier only needs to verify the validity of the final aggregated signature to prove the validity of these signatures,so it can reduce the communication burden and improve the efficiency of signature verification.However,in some cases,people's demand for information security is more complex,and they need to meet different security requirements at the same time,such as confidentiality,authentication,integrity and non-repudiation.In this case,encryption or signature alone cannot meet the actual requirements.The traditional method is to encrypt and sign in turn.Although it can meet these security requirements,the computation costs and communication costs almost are the sum of signature and encryption,which are very inefficient.Digital signcryption comes into being,it can complete both digital signature and data encryption in a logical step to ensure the confidentiality,integrity,non-repudiation and authentication of information at the same time.Compared with the traditional methods,digital signcryption has lower communication costs and higher efficiency.Scholars have done a lot of research on the aggregate signature and aggregate signcryption technology,they also designed many specific schemes.However,most of the existing schemes have the following problems:many schemes are vulnerable to the forgery attacks and are insecure;the final aggregated signature is easy to be linearly related to the number of messages,resulting in its long length;it is difficult to be applied to specific scenarios,etc.This paper tries to give solutions to these main problems on the basis of summarizing the advantages and disadvantages of the existing relevant schemes.The following is the main research contents:(1)Analyzes and improves an efficient certificateless aggregate signature scheme proposed by Kang et al.This paper analyzes the security of the scheme put forward by Kang et al.,and points out its security problems,that is,it cannot resist the forgery attack of type II adversary.In order to solve the above problem,this paper combines with the idea of revocability and constructs a revocable certificateless aggregate signature scheme with enhanced security.The scheme is not only secure,but also can revoke user flexibly to meet the actual scenarios.Secondly,the scheme has obvious advantages in the final aggregated signature length,computation costs,communication costs,etc.(2)Constructs four V2I secure communication signcryption schemes for heterogeneous vehicular ad hoc networks(VANETs).These schemes are not only secure,but also can meet the security requirements of confidentiality,authentication,integrity and non-repudiation at the same time.Moreover,they can realize the bi-directional communication in heterogeneous systems(PKI and IBC).Secondly,these schemes can verify the signcryption ciphertexts in batch and improve the efficiency of verification.Finally,compared with some existing schemes,the schemes in this paper have obvious advantages in computation costs,communication costs and storage space.