Research On Attribute-Based Keyword Search With Proxy Re-encryption Scheme

With the heat of cloud computing,more and more individuals and enterprises have uploaded large amounts of private data to the cloud to save local management and storage costs.But at the same time,cloud storage also brings many security problems.Searchable encryption enables quick retrieval of ciphertext using keywords without decrypting the ciphertext.In the background of cloud computing and big data sharing,more and more data is expected to be shared by more people,so attribute-based encryption with keyword search(ABKS)was proposed.ABKS scheme can not only support multiple users' keyword search for ciphertext,but also achieve fine control of search rights,which has become a research hotspot in cloud computing security.Aiming at the current problem that the attribute-based searchable encryption technology can not safely and effectively delegate the ciphertext search right to other users when the authorized users are not online,this thesis introduces proxy re-encryption technology into ABKS scheme and proposes an attribute-based keyword search with proxy re-encryption(ABRKS)scheme in cloud computing environment.In this thesis,three different ABRKS schemes are proposed according to the requirements of practical applications.The first scheme proposes an attribute-based keyword search with proxy re-encryption and designated keyword,which not only can realize the search of ciphertext,at the same time through the combination of proxy re-encryption also supports the search right of the designated keyword delegate to other users.The second scheme proposes an attribute-based proxy searchable encryption scheme supporting any keyword by using multi-linear mapping technology.It not only provides more flexibility,but also does not need to interact with the authorization center when the threshold is generated,which saves the computation and communication overhead and improves system performance.In addition,the existing ABKS schemes have the problem of leakage of user privacy by accessing the structure.A scheme of attribute-based searchable encryption that can hide part of the access structure is proposed.The scheme can not only hide the access structure realized the privacy protection,but also achieved the key update function in the re-encryption stage.This thesis analyzes the correctness of these schemes and proves the security of these schemes based on the assumption of security under the security model.The final theoretical analysis and experimental simulation show that these schemes are effective and practical.