Research On Security Mechanisms Of Outsourced Data

Cloud computing virtualizes the hardware and software resources of the remote data center and integrates them into a shared pool of configurable resources,then provides them to users as a service.The users use the resources in the pool as needed for data storage in the cloud.However,the uncertainty of cloud service providers and user devices poses new challenges for users' privacy protection and data security.In order to protect data security,this paper researches on the data integrity,confidentiality and reliability,and proposes the corresponding data security protection schemes.The contributions of this thesis are as follows:In terms of data integrity,this thesis combines Trusted Execution Environment and Identity-Based Aggregation Signatures to implement a secure and efficient cloud integrity verification scheme SIBAS.The scheme allows users to dynamically check the integrity of outsourced data,effectively reducing the time-consuming of integrity audit.In addition,security analysis shows that SIBAS meets the semantic security requirements of antiforgery attacks and can meet the security requirements in cloud computing environments.In terms of data confidentiality,this thesis proposes a privilege-based cloud deduplication scheme,which can provide fine-grained access control and encrypt metadata with convergent encryption to achieve balances in outsourced data confidentiality protection and deduplication across users.The security analysis and experimental results show that the scheme satisfies the semantic security requirements under the chosen distribution attacks.Considering for both data reliability and data confidentiality,this thesis combines Ciphertext-Policy Attribute-Based Encryption and blockchain to propose a secure data sharing scheme,which resorts to Ciphertext-Policy Attribute-Based Encryption for data encryption and supports for data flow tracing by controlling the key generation parameters sharing to ensure data confidentiality and reliability.Security analysis shows that the scheme has better resistance to chosen ciphertext attacks.