Task Matching Privacy Protection About Preventing Key Abuse And Revoking

With the rapid development of wireless communication and perception technology,crowdsensing system is used more and more widely,in which the number of participating users and tasks is more and more large,task matching service becomes particularly important.In the traditional scheme,only one authority is used to calculate the user key,which is easy to cause the performance bottleneck of the whole system,and the access structure uploaded to the incomplete trusted cloud server may also disclose the user privacy.Although the existing research schemes solve the problems of basic privacy protection and matching efficiency,most of the malicious users’ key abuse is only responsible and can not avoid the occurrence of this behavior.Secondly,preventing users from uploading data repeatedly is also a problem that has not been studied in detail in the existing scheme.In addition,many schemes carry out fine-grained revocation of users through re-encryption,which causes the system to bear heavy computational overhead and reduce matching efficiency.Therefore,in order to solve these problems,thesis designs a scheme to avoid key abuse while ensuring the privacy security of the crowdsensing task matching system,and can prevent users from uploading repeatedly at low overhead,and realize user fine-grained revocation scheme.it is of great significance for the privacy protection of task matching.The specific work of thesis is as follows:1)For the problems of privacy security and key abuse,thesis designs a task matching privacy protection scheme to prevent key abuse.Firstly,combined with the attribute encryption algorithm based on ciphertext policy,several attribute key authorization agencies are introduced to calculate the user key,and the system model is constructed.Then the new dynamic data structure constructed by counting Bloom filter and Merkel Patricia tree and its specific application methods are described in detail to avoid key abuse.Secondly,hide the upload access policy and provide task matching function in the case of protecting privacy and security.Finally,through experimental analysis,it is proved that the scheme can protect user and data privacy,resist user false identity attack,key abuse attack and coll usion attack between malicious user and cloud server,and the cost is low.2)In order to make the design scheme better meet the actual needs,prevent users from uploading the same data repeatedly and achieve fine-grained revocation,thesis adds the functions of identifying user repeated upload and attribute revocation based on the improved key abuse prevention scheme,a privacy protection scheme for preventing key abuse and revocable task matching is proposed.Firstly,the user information is perceived by changing the data structure,then the group signature technology based on zero knowledge proof is used to prevent malicious users from uploading repeatedly,and then the attribute revocation and user revocation of malicious users are realized by combining incremental hash.improve the efficiency of system data return.Finally,through experimental analysis,it is proved that the scheme can resist key abuse attack and collusion attack,guarantee forward security and backward security,and has low overhead under the premise of protecting privacy.