医疗信息化平台可验证的隐私保护数据搜索的研究

Patient privacy and correctness of data searching are most important for the Medical Information Platforms (MIPs). Motivated by the features of large datasets, frequent data update and multi-user data sharing on MIPs, this project focuses on the security requirements of verifiability and privacy preserving, and the functions of data sharing, general Boolean conjunctive search and parallel search of MIPs. Firstly, we introduce provable security theory and formal methodology and propose a new formal security model for the verifiable privacy preserving data search. Secondly, propose verifiable dynamic symmetric searchable encryption, based on which privacy-preserving data search protocol for single user is designed; Thirdly, propose known user-verifiable dynamic multi-user symmetric searchable encryption, based on which privacy-preserving authorized data search protocol is designed; Fourthly, propose unknown user-verifiable dynamic multi-user symmetric searchable encryption, where privacy preserving group sharing data search protocol is designed..In this proposal, the novel notion of verifiable set homomorphic signature is proposed to solve the problem of verifiability of search results. The new technique of third party based ORAM and two level search structure based on fuzzy trapdoor and accurate trapdoor are presented to meet the security properties of search mode privacy protection. The new approach of the index structure of “Oblivious Hierarchical Hash Tree with Links” is put forward to solve the problem of paralleled search and update..The project will empower the primitives of searchable encryption and homomorphic signature, and will promote the innovative development of medical information industry. It will significantly contribute to security theory, social life and economy.

医疗信息化平台数据搜索核心是搜索信息正确性与隐私保护。本课题旨在深入研究海量动态医疗数据搜索的可验证性和隐私保护安全性问题，以及共享式搜索、多维布尔组合搜索和并行搜索的功能性问题，内容包括：建立可验证的隐私保护数据搜索安全模型；研究可验证的动态对称可搜索加密，以此设计医疗数据自搜索方案；研究已知共享搜索者可验证的动态多方对称可搜索加密，以此设计授权搜索方案；研究未知共享搜索者可验证动态多方对称可搜索加密，以此设计群共享搜索方案。.本课题关键解决三个公开问题：首次提出可验证的集合同态签名解决搜索结果可验证问题；首次提出基于第三方的ORAM技术,和基于模糊陷门、精确陷门的两层搜索模式,解决搜索模式隐私性问题；首次提出不经意的带链分层哈希树索引结构解决数据搜索和更新的并行化问题。.本课题的研究将丰富可搜索加密和同态签名的密码学原语，并推动医疗信息化的发展，具有重要的理论价值、社会意义和经济意义。