| With the development of cloud computing and electronic commerce,many enterprises have migrated their applications and databases to the "cloud" and began to enjoy the advantages brought by cloud computing,such as on-demand computing resource configuration,flexible access control,and save a lot of capital expenditures,etc.,but also means that the data is at risk of misappropriation and misuse.Due to the limited computing and resource processing capabilities of cloud servers,the processing and storage of massive data will greatly reduce the efficiency of the system.The fog computing is a distributed computing that helps solve this problem.The introduction of fog calculation not only helps to solve the problem of limited computing power of IoT devices,but also effectively prevents the threat of cloud computing system overload.In view of the shortcomings of existing schemes.This paper focuses on the attribute encryption scheme that supports keyword search in cloud computing,and obtains the following research results.(1)Considering that the existing searchable encryption scheme has the problem of supporting only single keyword search and not supporting attribute revocation,and the single keyword search may cause partial errors in returning search results and lead to waste of calculation and broadband resources.With the help of third-party auditing ideas and attribute encryption technology,a verifiable multi-key word search encryption scheme supporting attribute revocation is proposed.By allowing the user to detect the correctness of the cloud server search results,the Lagrange interpolation formula is used to complete the attribute revocation of the user.The proposed scheme is proved to be resistant to selective keyword set attack security and keyword privacy based on the deterministic linear hypothesis and the discrete logarithm hypothesis in the random oracle model.(2)As an extension of cloud computing,fog computing outsources encrypted sensitive data to multiple fog nodes at the edge of the network to reduce latency and network congestion.However,existing ciphertext retrieval schemes are rarely based on fog calculations.With the ciphertext-based attribute encryption and searchable encryption technology,a novel searchable personal health record framework with fine-grained access control in cloud-fog computing is proposed.The scheme implements keyword search function and fine-grained access control.When the index and trapdoors match successfully,the cloud server returns the relevant personal health record file to the data user,thereby achieving a more accurate search.The scheme addresses the key leakage problem by dividing the user key distribution task.In addition,partial encryption and decryption oper ations are outsourced to the fog node to ease the computational and storage burden of the cloud server.Finally,based on the deterministic q-parallel bilinear Diffie-Hellman exponent hypothesis and the deterministic bilinear Diffie-Hellman hypothesis,this scheme proves to be indistinguishable to select ciphertext security and trapdoor privacy. |
