The new paradigm of outsourcing data to the cloud is a double-edged sword. On the one hand, it frees data owners from the technical management, and is easier for data owners to share their data with intended users. On the other hand, it poses new challenges on privacy and security protection. To protect data confidentiality against the honest-but-curious cloud service provider, numerous works have been proposed to support fine-grained data access control. However, till now, no schemes can support both fine-grained access control and time-sensitive data publishing. In this paper, by embedding timed-release encryption into Ciphertext-Policy Attribute-based Encryption (CP-ABE), we propose a new time and attribute factors combined access control on time-sensitive data for public cloud storage (named TAFC). Based on the proposed scheme, we further propose an efficient approach to design access policies faced with diverse access requirements for time-sensitive data. Extensive security and performance analysis shows that our proposed scheme is highly efficient and satisfies the security requirements for time-sensitive data storage in public cloud.

中文翻译：

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TAFC：公共云中时间敏感数据的时间和属性因素联合访问控制

将数据外包到云端的新范式是一把双刃剑。一方面，它将数据所有者从技术管理中解放出来，并且数据所有者更容易与目标用户共享他们的数据。另一方面，它对隐私和安全保护提出了新的挑战。为了保护诚实但好奇的云服务提供商的数据机密性，已经提出了许多支持细粒度数据访问控制的工作。然而，到目前为止，没有任何方案可以同时支持细粒度访问控制和时间敏感的数据发布。在本文中，通过将定时发布加密嵌入到基于密文策略属性的加密（CP-ABE）中，我们提出了一种新的时间和属性因素结合的公共云存储时间敏感数据访问控制（命名为 TAFC）。根据提议的方案，我们进一步提出了一种有效的方法来设计面对时间敏感数据的不同访问要求的访问策略。广泛的安全和性能分析表明，我们提出的方案是高效的，满足公共云中时间敏感数据存储的安全要求。