A provably secure certificateless public key encryption with keyword search

ABSTRACT

Public key encryption with keyword search, known as PEKS, is a useful technology in some Storage-as-a-Service clouds. This technology allows the cloud server to search on a keyword, which is received from the data owner/user, over encrypted data without having the ability to decrypt the stored data. PEKS with designated verifier, known as dPEKS, further advances the security of PEKS such that only a designated server can perform the keyword searching.

Combining the certificateless technology, which aims to avoid the key escrow problem in ID-based cryptography, produces a certificateless dPEKS scheme that inherits the property of certificatelessness in key management in the dPEKS. This paper presents a provably secure certificateless dPEKS which has fixed an insecure scheme which was proposed earlier. The scheme presented in this paper is proven to be secure under Bilinear Diffie–Hellman problem.

KEYWORDS:

• PEKS
• certificateless
• off-line keyword guessing attacks
• provably secure

Acknowledgments

The authors would like to thank the reviewers’ constructive suggestions and comments. The work was supported in part by Shenzhen Technical Project under Grant number JCYJ20170307151750788 and in part by Shenzhen Technical Project under Grant number KQJSCX20170327161755.

Disclosure statement

No potential conflict of interest was reported by the authors.

Nomenclature

Tadd	=	The execution time of one modular addition operation
Texp	=	The execution time of one modular exponentiation operation
TH	=	The execution time of one addition operation H2, H4
TGadd	=	The execution time of one addition operation in G1
TGe	=	The execution time of one bilinear pairing operation e
TGH	=	The execution time of one map-to-point hash function H1, H3
TGmul	=	The execution time of one scalar multiplication operation in G1

Additional information

Funding

The Work of Eric Ke Wang was supported in part by National Natural Science Foundation of China (No.61572157), grant No.2016A030313660 from Guangdong Province Natural Science Foundation, JCYJ20160608161351559 from Shenzhen Municipal Science and Technology Innovation Project..