Design And Implementation Of Data Security Access Control System Based On Cloud And Blockchian Integration

With the widely used of intelligent mobile terminals,people's life has significantly changed in flexibility.However,as mobile terminals are limited by hardware resources such as power,computing power,and storage capacity,users prefer to use the mobile cloud to store and share personal data.But users have totally lost control over the outsourced data,and the cloud service provider is snooping into the users' data as much as possible to explore the potential value of the data for their benefit.So how to ensure data security in a mobile cloud environment has been a hot topic of research.Current data access control system solutions for mobile cloud have the following shortcomings: centralized cloud services and third-party key management agencies are semi-trustworthy,and data stored in semi-trustworthy environments have the problem of being easily compromised;data usage history is not disclosed to users;most systems adopt ciphertext access control policies that fail to achieve granular access control.To this end,this thesis proposes a Data Security Access Control System Based on Cloud and Blockchain Integration(CBDS)to solve the above issues.In CBDS,a new cloud and blockchain integration architecture for secure access control of cloud has been designed by utilizing the advantages of blockchain and cloud storage;the CBDS-CP-ABE algorithm is designed to realize fine-grained access control based on Attribute-Based Encryption;the logical rules of the system and data access control management rules are realized using smart contracts;the framework of data security access control system is given,and the application process of each module in the framework is elaborated.This thesis conducts experimental evaluation and security analysis of CBDS system.The results shows that CBDS system has similar performance compared to the traditional data access control system,and users have higher control and management rights over personal data in the cloud,users can more securely share data and keep track of personal data usage,in addition,blockchain stores the data usage history information,the system has good availability,stability,security,and scalability.