Access Control Mechanism Of Data Sharing In Cloud Storage Based On Blockchain

With the advance of network technology,there are more and more scenarios for data exchange between different enterprise or organizations in real business scenarios.Therefore,people pay more and more attention to the access control of the shared data.In traditional cloud storage systems,a centralized access control architecture is usually adopted,which is vulnerable to hacker attacks,and there are problems of single point of failure and privacy leakage.At the same time,the shared data stored in the cloud server also has the potential to be forged and tampered.In the real business scenario,the process of data access across organizations is complex and time-consuming,and business process automation needed to be realized.On the other hand,with the rise of cryptocurrency,blockchain technology has gradually attracted people's attention.Scholars introduce blockchain technology into cloud storage scenarios,its decentralization,distributed storage and non-tampering characteristics have brought new solution to the above problems.In the scenario of cloud storage data sharing between enterprises or organizations,this paper studies blockchain smart contract technology and attribute-based encryption algorithms to solve the above problems.The specific work is as follows:(1)Propose an access control mechanism for cloud storage scenarios,solves the problems of data tampering and single point of failure that may exist in the original centralized scheme based on the attribute-based encryption algorithm.Specifically,blockchain smart contract is introduced in the original scheme to achieve access control function,and at the same time,the certificate distribution mechanism of the original blockchain CA is used to realize the distribution scheme of the attribute key,a data encryption and decryption scheme that combines attribute-based encryption algorithms and symmetric encryption algorithms is adopted,which improves the security of the distribution of the attribute key and solves the problem of low encryption and decryption efficiency in the original scheme.(2)Propose a smart contract-based access control method,which solves the problem that access control rules cannot supervise malicious behaviors that occur in actual scenarios.The access control method proposed in this paper include static and dynamic access control methods.The static access control method is used to determine whether the user attributes meet the access control rules,and the dynamic access control method is used to determine whether the user has malicious behavior and give corresponding punishments.At the same time,information related to user privacy is maintained in another blockchain,which improves data security and privacy protection.(3)Propose a blockchain-based cloud storage shared data access control system based on the above two aspects of work,including the system architecture and specific shared data storage and acquisition schemes.Using Java to simulate the system architecture of the blockchain,realize the prototype system of the scheme in this paper.Finally,the comparison with other solutions shows that the blockchain-based cloud storage shared data access control mechanism proposed in this paper is superior to the comparison solution in terms of data security and privacy.At the same time,the data storage and acquisition delay are meet the needs of cloud storage scenarios,and it has better performance in terms of data encryption and decryption efficiency,storage overhead and scalability,so the scheme in this paper has better applicability in cloud storage scenarios.