Research On Dynamic And Multi-Authority Attribute-Based Encryption Scheme With Outsourced Auditing In The Cloud

Attribute-based Encryption(ABE)is an access control-based solution that allows data owners to set access control policies for their data,ensuring that only users who meet the specified policies can decrypt their data,thus protecting against unauthorized access and theft.In this new many-to-many encryption paradigm,the encryptor does not know who can decrypt the ciphertext,and the receiver does not know who the encryptor is,which to a certain extent provides privacy protection for both sides of the interaction and finegrained access control for the data storage in the cloud,making data management more secure and controllable.However,the existing ABE schemes cannot well meet the dynamic requirements of various system entities due to the continuous improvement of hardware infrastructure technology and the enrichment of user usage scenarios.At present,most attribute-based encryption schemes are static and their related parameters need to be fixed from the beginning,thus limiting the flexibility of the system.In addition,some outsourcing solutions in the past only handled complex calculations independently,without in-depth discussion on the correctness of the returned results and the integrity of the data content,which also brought serious security threats to users’ privacy information.To address these challenges,our work proposes a dynamic multi-authority ABE scheme that is more flexible,efficient,and secure,making it more applicable to the cloud storage environment.Firstly,we address the limitations of existing ABE schemes,such as fixed parameters,poor system flexibility,and limited applications.To overcome these issues,the proposed scheme associates multiple authorities with dynamic characteristics in the ABE algorithm,allowing for the setting of dynamic multiple authorities.This enables support for dynamic changes in system members,authorities,and attribute values,resulting in a more flexible system state and more secure access control.Secondly,considering the issue of data privacy leakage due to the lack of verification of outsourcing results in existing solutions,we propose a double audit verification of outsourcing results without introducing additional third-party auditors.This approach reduces the decryption cost on the user side to a constant level while ensuring the correctness of decryption and data integrity,thus achieving more secure and efficient decryption outsourcing calculations.Finally,in response to the security threats in existing attribute-based encryption,we reduce the scheme to the Decisional Bilinear Diffie-Hellman(DBDH)problem under the standard model and proves that the scheme can achieve security against chosen-ciphertext attacks.The outsourcing audit security of the proposed scheme is demonstrated under the fully credible setting of the central authority.Furthermore,the scheme is proven to be secure against malicious users and malicious attribute authorities from the perspective of key distribution and double audit,providing a more secure guarantee for the flexible deployment of the system in practical scenarios.In conclusion,the proposed scheme has practical significance and application value in realizing data security control in the cloud storage environment.It provides a more practical and flexible solution for dynamic multi-authority attribute-based encryption related construction supporting privacy protection in the cloud.