Abstract: searchable public key encryption enables a storage server to retrieve the publicly encrypted data without revealing the original data contents. It offers a perfect cryptographic solution to encrypted data retrieval in encrypted data storage systems. Certificateless cryptography (CLC) is a novel cryptographic primitive that has many merits. It overcomes the key escrow problem in identity-based cryptosystems and the cumbersome certificate problem in conventional public key cryptosystems. Motivated by the appealing features of CLC, three certificateless encryption with keyword search (CLEKS) schemes were presented in the literature. However, all of them were constructed with the costly bilinear pairing and thus are not suitable for the devices that have limited computing resources and battery power. So, it is interesting and worthwhile to design a CLEKS scheme without using bilinear pairing. In this study, we put forward a pairing-free CLEKS scheme that does not exploit bilinear pairing. We strictly prove that the scheme achieves keyword ciphertext indistinguishability against adaptive chosen-keyword attacks under the complexity assumption of the computational Diffie-Hellman problem in the random oracle model. Efficiency comparison and the simulation show that it enjoys better performance than the previous pairing-based CLEKS schemes. In addition, we briefly introduce three extensions of the proposed CLEKS scheme.

不依赖双线性对的带关键字搜索的无证书公钥加密方案构造

[1]Abdalla M, Bellare M, Catalano D, et al., 2008. Searchable encryption revisited: consistency properties, relation to anonymous IBE, and extensions. J Cryptol, 21(3):350- 391.

[2]Al-Riyami SS, Paterson KG, 2003. Certificateless public key cryptography. Proc 9^th Int Conf on the Theory and Application of Cryptology and Information Security, p.452- 473.

[3]Baek J, Safavi-Naini R, Susilo W, 2008. Public key encryption with keyword search revisited. Proc 7^th Int Conf on Computational Science and Its Applications, p.1249- 1259.

[4]Bellare M, Rogaway P, 1993. Random oracles are practical: a paradigm for designing efficient protocols. Proc 1^st ACM Conf on Computer and Communications Security, p.62-73.

[5]Boneh D, di Crescenzo G, Ostrovsky R, et al., 2004. Public key encryption with keyword search. Proc Int Conf on the Theory and Applications of Cryptographic Techniques, p.506-522.

[6]Byun JW, Lee DH, Lim J, 2006. Efficient conjunctive keyword search on encrypted data storage system. Proc 3^rd European PKI Workshop, p.184-196.

[7]Canetti R, Goldreich O, Halev S, 2004. The random Oracle methodology, revisited. J ACM, 51(4):557-594.

[8]Dong QX, Guan Z, Wu L, et al., 2013. Fuzzy keyword search over encrypted data in the public key setting. Proc 14^th Int Conf on Web-Age Information Management, p.729-740.

[9]Fang LM, Susilo W, Ge P, et al., 2009. A secure channel free public key encryption with keyword search scheme without random oracle. Proc 8^th Int Conf on Cryptology and Network Security, p.248-258.

[10]Fu ZJ, Sun XM, Liu Q, et al., 2015. Achieving efficient cloud search services: multi-keyword ranked search over encrypted cloud data supporting parallel computing. IEICE Trans Commun, E98.B(1):190-200.

[11]Fu ZJ, Ren K, Shu JG, et al., 2016. Enabling personalized search over encrypted outsourced data with efficiency improvement. IEEE Trans Parall Distrib Syst, 27(9): 2546-2559.

[12]Golle P, Staddon J, Waters B, 2004. Secure conjunctive keyword search over encrypted data. Proc 2^nd Int Conf on Applied Cryptography and Network Security, p.31-45.

[13]Guo LF, Yau WC, 2015. Efficient secure-channel free public key encryption with keyword search for EMRs in cloud storage. J Med Syst, 39(2):1-11.

[14]Hu CY, Liu PT, 2012. An enhanced searchable public key encryption scheme with a designated tester and its extensions. J Comput, 7(3):706-715.

[15]Hwang YH, Lee PJ, 2007. Public key encryption with conjunctive keyword search and its extension to a multi-user system. Proc 1^st Int Conf on Pairing-Based Cryptography, p.2-22.

[16]Islam SH, Obaidat MS, Rajeev V, et al., 2017. Design of a certificateless designated server based searchable public key encryption scheme. Proc 3^rd Int Conf on Mathematics and Computing, p.3-15.

[17]Li JG, Lin XN, Zhang YC, et al., 2017a. KSF-OABE: outsourced attribute-based encryption with keyword search function for cloud storage. IEEE Trans Serv Comput, 10(5):715-725.

[18]Li JG, Shi YR, Zhang YC, 2017b. Searchable ciphertext- policy attribute-based encryption with revocation in cloud storage. Int J Commun Syst, 30(1):1-13.

[19]Liu JN, Lai JZ, Huang XY, 2017. Dual trapdoor identity-based encryption with keyword search. Soft Comput, 21(10): 2599-2607.

[20]Lu Y, Wang G, Li JG, et al., 2017. Efficient designated server identity-based encryption with conjunctive keyword search. Ann Telecommun, 72(5-6):359-370.

[21]Lv ZQ, Hong C, Zhang M, et al., 2014. Expressive and secure searchable encryption in the public key setting. Proc 17^th Int Conf on Information Security, p.364-376.

[22]MIRACL Ltd., 2012. MIRACL Cryptographic SDK: Multiprecision Integer and Rational Arithmetic Cryptographic Library. https://github.com/miracl/MIRACL

[23]Park DJ, Kim K, Lee PJ, 2004. Public key encryption with conjunctive field keyword search. Proc 5^th Int Workshop on Information Security Applications, p.73-86.

[24]Peng YG, Cui JT, Peng CG, et al., 2014. Certificateless public key encryption with keyword search. China Commun, 11(11):100-113.

[25]Rhee HS, Park JH, Susilo W, et al., 2010. Trapdoor security in a searchable public-key encryption scheme with a designated tester. J Syst Softw, 83(5):763-771.

[26]Shamir A, 1984. Identity-based cryptosystems and signature schemes. Proc 1^st Workshop on the Theory and Application of Cryptographic Techniques, p.47-53.

[27]Shao ZY, Yang B, 2015. On security against the server in designated tester public key encryption with keyword search. Inform Process Lett, 115(12):957-961.

[28]Shi J, Lai JZ, Li YJ, et al., 2014. Authorized keyword search on encrypted data. Proc 1^st European Symp on Research in Computer Security, p.419-435.

[29]Siad A, 2012. Anonymous identity-based encryption with distributed private-key generator and searchable encryption. Proc 5^th Int Conf on New Technologies, Mobility and Security, p.1-8.

[30]Song DX, Wagner D, Perrig A, 2000. Practical techniques for searches on encrypted data. Proc IEEE Symp on Security and Privacy, p.44-55.

[31]Standards for Efficient Cryptography Group, 2000. SEC 2: Recommended Elliptic Curve Domain Parameters, Version 1.0. http://www.secg.org/SEC2-Ver-1.0.pdf

[32]Sun WH, Yu SC, Lou WJ, et al., 2016. Protecting your right: verifiable attribute-based keyword search with fine- grained owner-enforced search authorization in the cloud. IEEE Trans Parall Distrib Syst, 27(4):1187-1198.

[33]Tian XX, Wang Y, 2008. ID-based encryption with keyword search scheme from bilinear pairings. Proc 4^th Int Conf on Wireless Communications, Networking and Mobile Computing, p.1-4.

[34]Tomida K, Doi H, Mohri M, et al., 2015. Ciphertext divided anonymous HIBE and its transformation to identity-based encryption with keyword search. J Inform Process, 23(5): 562-569.

[35]Wang XF, Mu Y, Chen RM, et al., 2016. Secure channel free ID-based searchable encryption for peer-to-peer group. J Comput Sci Technol, 31(5):1012-1027.

[36]Wu TY, Tsai TT, Tseng YM, 2014. Efficient searchable ID- based encryption with a designated server. Ann Telecomm, 69(7-8):391-402.

[37]Zhang B, Zhang FG, 2011. An efficient public key encryption with conjunctive-subset keywords search. J Netw Comput Appl, 34(1):262-267.

[38]Zheng QJ, Xu SH, Ateniese G, 2014. VABKS: verifiable attribute-based keyword search over outsourced encrypted data. Proc IEEE INFOCOM, p.522-530.

[39]Zheng QJ, Li XX, Azgin A, 2015. CLKS: certificateless keyword search on encrypted data. Proc 9^th Int Conf on Network and System Security, p.239-253.