Expressive Attribute-based Searchable Encryption Scheme in Cloud Computing

Abstract

Searchable encryption technology can realize keyword search without decrypting the data,and thus well protects user'sprivate information.Aiming at the problem that most current searchable encryption schemes cannot support user-defined search strategies,this paper proposes an attribute-based searchable encryption scheme which is secure,efficient and can support arbitrary search expressions.Firstly,the scheme,based on LSSS access structure,allows keyword search policy to be represented by conjunction,disjunction or any monotone Boolean expression,user generates trapdoor for LSSS search policy by utilizing the private key,and cloud server can search ciphertexts that satisfy specific keywords search policy through trapdoor.Secondly,it can realize fine-grained access control of encrypted data in cloud through combining with attribute-based encryption scheme.In addition,attackers cannot infer the sensitive information of keyword values from ciphertext and trapdoor by splitting keywords into keyword names and values through "linear splitting" technology.Finally,the computing burden of users is reduced due to part of decryption work is transfered to cloud server.The security of the proposed scheme is proved based on BDHE,(q-2) assumption.Theoretical analysis and experimental results also show that the scheme is effective.

Keywords

• cloud computing|data sharing|attribute -based encryption|searchable encryption|keywords search policy