中文摘要：

医疗卫生领域形成的医疗大数据中包含了大量的个人隐私信息,面临着外部攻击和内部泄密的潜在安全隐患。传统的访问控制模型没有考虑用户访问目的在侧重数据隐私的访问控制中的重要作用,现有的对称、非对称加密技术又都存在密钥管理、证书管理复杂的问题。针对这些问题,提出了综合应用PBAC模型和IBE加密技术的访问控制方案,支持针对医疗数据密文的灵活访问控制。通过加入条件目的概念对PBAC模型进行扩展,实现了对目的树的全覆盖;以病患ID、条件访问位和预期目的作为IBE身份公钥进行病患数据加密,只有通过认证并且访问目的符合预期的用户才能获得相应的私钥和加密数据,从而实现对病患信息的访问。实验结果证明,该方案达到了细粒度访问控制和隐私保护的目的,并具有较好的性能。

英文摘要：

Due to the large amount of personal privacy information contained, the medical big data formed in the health care industry was faced with potential threats of both external attacks and internal data leakages. However, traditional access control technology didn＇t take into account the important role of user access purpose in the access control schemes that emphasized data privacy, and existing symmetric and asymmetric encryption technologies both face problems such as the complexity of key and certificate management. To address these problems, a novel access control scheme based on PBAC model and IBE encryption technology was proposed, which could provide flexible access control of encrypted medical data. By introducing the concept of conditioned purpose, the PBAC model was extended to achieve full coverage of purpose trees. Furthermore, the scheme used patient ID, conditioned bit and intended purpose as the IBE public key,with which patients＇ data were encrypted. Only users who pass the authentication and whose access purposes conform to the intended purposes can obtain the corresponding private keys and the encrypted data, thereby achieving access to patients＇ information. Experimental results prove that the scheme can achieve the goals of fine-grained access control and privacy protection with high performance.