title: Secure medical information sharing in cloud computing.
abstract: Medical information sharing is one of the most attractive applications of cloud computing, where searchable encryption is a fascinating solution for securely and conveniently sharing medical data among different medical organizers. However, almost all previous works are designed in symmetric key encryption environment. The only works in public key encryption do not support keyword trapdoor security, have long ciphertext related to the number of receivers, do not support receiver revocation without re-encrypting, and do not preserve the membership of receivers. In this paper, we propose a searchable encryption supporting multiple receivers for medical information sharing based on bilinear maps in public key encryption environment. In the proposed protocol, data owner stores only one copy of his encrypted file and its corresponding encrypted keywords on cloud for multiple designated receivers. The keyword ciphertext is significantly shorter and its length is constant without relation to the number of designated receivers, i.e., for n receivers the ciphertext length is only twice the element length in the group. Only the owner knows that with whom his data is shared, and the access to his data is still under control after having been put on the cloud. We formally prove the security of keyword ciphertext based on the intractability of Bilinear Diffie-Hellman problem and the keyword trapdoor based on Decisional Diffie-Hellman problem.
authors.affiliation: School of Computer Science, Shaanxi Normal University, Xi'an, Shaanxi, China.|Science and Technology on Communication Security Laboratory, Chengdu, Sichuan, China.|State Key Laboratory of Information Security, Beijing, China.
authors.forename: Zhiyi
authors.initials: Z
authors.lastname: Shao
authors.affiliation: School of Computer Science, Shaanxi Normal University, Xi'an, Shaanxi, China.|Science and Technology on Communication Security Laboratory, Chengdu, Sichuan, China.|State Key Laboratory of Information Security, Beijing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.affiliation: Science and Technology on Communication Security Laboratory, Chengdu, Sichuan, China.
authors.forename: Wenzheng
authors.initials: W
authors.lastname: Zhang
authors.affiliation: School of Computer Science, Shaanxi Normal University, Xi'an, Shaanxi, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: School of Computer Science, Shaanxi Normal University, Xi'an, Shaanxi, China.
authors.forename: Zhenqiang
authors.initials: Z
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Integrated Service Networks, Xidian University, Xi'an, Shaanxi, China.
authors.forename: Meixia
authors.initials: M
authors.lastname: Miao
mesh_terms: D000465:Algorithms; D000067917:Cloud Computing; D016494:Computer Security; D003219:Confidentiality; D066275:Health Information Exchange; D006801:Humans; D016247:Information Storage and Retrieval
keywords: Medical information sharing; ciphertext security; multiple receivers; searchable encryption; trapdoor security