Efficient and expressive keyword search over encrypted data in the cloud

• Main Authors: CUI, Hui, WAN, Zhiguo, DENG, Robert H., WANG, Guilin, Yingjiu LI
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2018
• Subjects: attribute-based encryption; Searchable encryption; cloud computing; expressiveness; Information Security
• Online Access: https://ink.library.smu.edu.sg/sis_research/3380; https://ink.library.smu.edu.sg/context/sis_research/article/4381/viewcontent/EfficientandExpressiveKeywordSearchOverEncryptedDataintheCloud.pdf
• Institution: Singapore Management University

Searchable encryption allows a cloud server to conduct keyword search over encrypted data on behalf of the data users without learning the underlying plaintexts. However, most existing searchable encryption schemes only support single or conjunctive keyword search, while a few other schemes that are able to perform expressive keyword search are computationally inefficient since they are built from bilinear pairings over the composite-order groups. In this paper, we propose an expressive public-key searchable encryption scheme in the prime-order groups, which allows keyword search policies (i.e., predicates, access structures) to be expressed in conjunctive, disjunctive or any monotonic Boolean formulas and achieves significant performance improvement over existing schemes. We formally define its security, and prove that it is selectively secure in the standard model. Also, we implement the proposed scheme using a rapid prototyping tool called Charm [37], and conduct several experiments to evaluate it performance. The results demonstrate that our scheme is much more efficient than the ones built over the composite-order groups.