Paper 2022/614

PPRKS: A Privacy Preserving Range Keyword Search Scheme

Abstract

Privacy preserving keyword search (PPKS) is investigated in this paper, which aims to ensure the privacy of clients and servers when a database is accessed. Range query has been recognized as a common operation in databases. In this paper, a formal definition of PPKS supporting range query is given, a scheme (PPRKS) is presented in accordance with Paillier’s cryptosystem. To the best of our knowledge, PPRKS has been the only existing scheme that can effectively preserve the privacy of range keyword search. Moreover, it is demonstrated that the security of PPRKS is dependent on the semantic security of Paillier’s cryptosystem. A detailed performance analysis and a simulation are conducted to verify the practicality of PPRKS. As revealed by the theoretical analysis and the experimental results, the proposed scheme is practical.