Fine-grained Access Strategy Based On Improved Proxy Re-encryption In Cloud Environment

With the advancement of information technology and the improvement of basic computer services,cloud services have developed more comprehensively and accurately.The scalability,ease of management,and fast response speed of cloud services have attracted a large number of enterprises and users to store data in the cloud.Cloud services are convenient and reduce the investment of enterprises and individual users in infrastructure.However,when users store data in the cloud,their data faces unpredictable security risks.In response to the user's data security issue,a Fine-grained Access Strategy Based on Improved Proxy Re-encryption in Cloud Environment(FASIPRE)is proposed.The FASIPRE scheme ensures data confidentiality.It also improves the efficiency of algorithm execution and large-storage data processing.The main research contents of the thesis are as follows:First,study the existing proxy re-encryption algorithm and improve the algorithm.By reducing the bilinear mapping,the goal of reducing the operating cost of the system is achieved.In the improved proxy re-encryption technology,the data owner uses the key generated by the trusted key generation center and the fine-grained control access policy information and related parameters to encrypt the plaintext of the data into ciphertext.In the process,the calculation of bilinear mapping is reduced,and the computing resource consumption of the system is reduced.Then,on the basis of the improved proxy re-encryption,the improved attribute-based encryption is incorporated into the access policy,and the permissions to access the ciphertext data are assigned according to the access policy set by the data owner,and users who meet the attribute set in the access policy Only then can the ciphertext data be obtained.The paper uses improved proxy re-encryption technology combined with attribute-based encryption algorithms to prevent external and internal attacks,provide users with fine-grained access control,and enhance the security of user data information access control in the cloud environment.Finally,test the core algorithm of the FASIPRE scheme from different dimensions.The dimensions mainly include: the number of attributes in the fine-grained scheme,the time complexity,and the time consumption of encryption and decryption at each stage;the HA high-availability architecture is built on the Hadoop platform,and then the core algorithm of the FASIPRE scheme is deployed in the MapReduce parallel processing framework to test and analyze data of different capacities.The experimental results show that the algorithm execution efficiency in the FASIPRE scheme has obvious advantages.The improved algorithm reduces the number of bilinear operations in the initial encryption phase,re-encryption phase,and decryption phase.The time complexity of the algorithm is relatively low.Compared with other programs in recent years,the consumption is significantly reduced.In addition,the improved algorithm is deployed in the MapReduce parallel computing framework.As the text capacity doubles,the time to process data increases rapidly,but its growth rate is less than 1 compared with the multiple of the text capacity increase;the algorithm in the FASIPRE scheme It can be reasonably deployed in MapReduce and run normally.