The e-healthcare cloud system has shown its potential to improve the quality of healthcare and individuals' quality of life. Unfortunately, security and privacy impede its widespread deployment and application. In this paper, we design an inference attack-resistant e-healthcare cloud system with fine-grained access control. We first propose a two-layer encryption scheme. To ensure an efficient and fine-grained access control over the EHR data, we design the first-layer encryption, where we devise a specialized access structure for each data attribute in the EHR, and encrypt them individually with high efficiency. To preserve the privacy of role attributes and access structures used in the first-layer encryption, we systematically construct the second-layer encryption. To take full advantage of the cloud server, we propose to let the cloud execute computationally intensive works on behalf of the data user without knowing any sensitive information. To preserve the access pattern of data attributes in the EHR, we further construct a blind data retrieving protocol. We also demonstrate that our scheme can be easily extended to support search functionality. Finally, we conduct extensive security analyses and performance evaluations, which confirm the efficacy and efficiency of our scheme.

中文翻译：

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具有细粒度访问控制的抗推理攻击电子医疗云系统

电子医疗保健云系统已显示出其改善医疗保健质量和个人生活质量的潜力。不幸的是，安全和隐私阻碍了其广泛部署和应用。在本文中，我们设计了一个具有细粒度访问控制的抗推理攻击的电子医疗云系统。我们首先提出了一个两层加密方案。为了确保对 EHR 数据的高效细粒度访问控制，我们设计了第一层加密，我们为 EHR 中的每个数据属性设计了专门的访问结构，并对其进行了高效的单独加密。为了保护第一层加密中使用的角色属性和访问结构的隐私，我们系统地构建了第二层加密。充分利用云服务器，我们建议让云代表数据用户执行计算密集型工作，而无需知道任何敏感信息。为了保留 EHR 中数据属性的访问模式，我们进一步构建了一个盲数据检索协议。我们还证明了我们的方案可以轻松扩展以支持搜索功能。最后，我们进行了广泛的安全分析和性能评估，这证实了我们方案的有效性和效率。