Ciphertext-policy attribute-based encryption with hidden sensitive policy from keyword search techniques in smart city

EURASIP Journal on Wireless Communications and Networking

Leixiao Cheng¹  Mingqiang Wang²  Fei Meng² 

[1] School of Mathematics, Shandong University, South Shanda Road, No. 27, 250100, Jinan, China;School of Mathematics, Shandong University, South Shanda Road, No. 27, 250100, Jinan, China;Key Laboratory of Cryptologic Technology and Information Security, Ministry of Education, South Shanda Road, No. 27, 250100, Jinan, China;

关键词: Smart city;    Attribute-based encryption;    Hidden sensitive policy;    Keyword search;    Fog nodes;   

DOI  :  10.1186/s13638-020-01875-2

来源: Springer

【 摘 要 】

Countless data generated in Smart city may contain private and sensitive information and should be protected from unauthorized users. The data can be encrypted by Attribute-based encryption (CP-ABE), which allows encrypter to specify access policies in the ciphertext. But, traditional CP-ABE schemes are limited because of two shortages: the access policy is public i.e., privacy exposed; the decryption time is linear with the complexity of policy, i.e., huge computational overheads. In this work, we introduce a novel method to protect the privacy of CP-ABE scheme by keyword search (KS) techniques. In detail, we define a new security model called chosen sensitive policy security: two access policies embedded in the ciphertext, one is public and the other is sensitive andhidden. If user's attributes don't satisfy the public policy, he/she cannot get any information (attribute name and its values) of the hidden one. Previous CP-ABE schemes with hidden policy only work on the “AND-gate” access structure or their ciphertext size or decryption time maybe super-polynomial. Our scheme is more expressive and compact. Since, IoT devices spread all over the smart city, so the computational overhead of encryption and decryption can be shifted to third parties. Therefore, our scheme is more applicable to resource-constrained users. We prove our scheme to be selective secure under the decisional bilinear Diffie-Hellman (DBDH) assumption.

【 授权许可】

CC BY