Research On Shared Data Security Audit Technology In Cloud Storage

With the rapid development of cloud computing technology,the quality of cloud storage services is constantly improving,and users' data can be stored not only in the cloud but also in groups.Group member users create data and share it with other valid members in the group,while valid member users in the group can access and modify these shared data.However,the cloud data sharing service brings great convenience to users,and also brings new problems such as user identity privacy protection and data block signer identity tracking to the data security audit work in cloud storage.The development of storage has brought unprecedented challenges.When a third-party auditor performs security auditing on shared data,the identity information of the group member user may be obtained by the signature of the data block to be verified,and the identity privacy of the data block signature user is destroyed;the anonymous signature technology can implement the privacy protection of the data block signer identity,but the user identity that may cause malicious tampering with data cannot be revealed;as a group sharing data in the cloud,once a member user joins or revokes from the group,whether other members in the group will be affected,and is it necessary recalculating the verification signature information;user computing overhead and communication overhead in the group and the efficiency of shared data security auditing are also an important issue.In view of the above problems,this paper studies the cloud shared data security audit technology.The main work is as follows:(1)This paper summarizes the research status of data security audit in cloud storage at home and abroad,introduces the related technologies of shared data security audit,and analyzes the current classic shared data security audit method.(2)Aiming at the problem of shared data signature user identity tracking,large user computation and low audit efficiency in cloud storage,the improvement of group shared data auditing method in cloud storage is studied,and use the nature of bilinear pair mapping on elliptic curve to perform data integrity verification to implement public audit,use security a mediator to replace group members to sign data blocks to protect group membership privacy,and design a data block trace table to implement identity trackingof data block signers.Safety analysis and efficiency analysis of the method were carried out;the experiment was designed and the experimental results were analyzed.(3)Aiming at the low efficiency and low real-time performance of data signature and batch audit process in cloud storage shared data auditing process,this paper studies the cloud storage shared data auditing method based on Spark Streaming,and submits the user's uploading data block signature task to the trusted agent signing party to complete;the trusted agent signing party processes the user data block signing task in parallel;the third party auditor verifies the evidence in parallel to realize the parallelization of the auditing process;the experiment was designed,and the experimental result was analyzed.The innovation of the paper includes:(1)An improved auditing method based on elliptic curve encryption for cloud storage group sharing data was proposed,which realizes public audit of cloud shared data and the protection of group member user privacy and the user identity of maliciously modifying shared data during auditing.The tracking and security analysis show that the method can effectively resist the enemy attack.The experimental results show that the method can effectively complete the security audit work of shared data in the cloud and reduce the computational load of the client.(2)A shared data auditing method based on Spark Streaming was proposed.The user data block signing task and the third-party auditor's batch audit process are parallelized.The experimental results show that the method effectively improves the audit real-time and efficiency and reduces the user's calculation.