A Framework of Secure Delivery Service for Targeted Coupons with Encrypted Search

A framework of secure delivery service of targeted coupons with encrypted search is proposed to solve privacy issues of users and vendors in delivery service of mobile targeted coupons. The proposed framework adopts a newly developed cryptographic primitive, called multi-key searchable encryption, which ensures that a user only needs to submit a single encrypted request to the coupon site so as to conduct secure and effective search over encrypted coupons from different vendors. Meanwhile, the framework ensures that eligible users can obtain targeted coupons without leaking their behavioral data while non-eligible users learn nothing beyond their non-eligibility status by combining locality-sensitive hashing with password authenticated key exchange. Theoretical analysis proves the security of the proposed framework. Extensive experiments show that when a mobile user obtains coupons from 10 different vendors, the computation cost of the proposed framework is 57.8 ms, bandwidth cost 2.9 KiB, and energy cost 8.7 J. The proposed framework provides a well-balanced tradeoff between security and efficiency, and has certain theoretical and practical significance for the design of secure and practical targeted delivery systems.