Cloud-based Internet of Things, which is considered as a promising paradigm these days, can provide various applications for our society. However, as massive sensitive and private data in IoT devices are collected and outsourced to cloud for data storage, processing, or sharing for cost saving, the data security has become a bottleneck for its further development. Moreover, in many large-scale IoT systems, multiple group data sharing is practical for users. Thus, how to ensure data security in multiple group data sharing remains an open problem, especially the fine-grained access control and data integrity verification with public auditing. Therefore, in this paper, we propose a blockchain-based fine-grained data sharing scheme for multiple groups in cloud-based IoT systems. In particular, we design a novel multiauthority large universe CP-ABE scheme to guarantee the fine-grained access control and data integrity across multiple groups by integrating group signature into our scheme. Moreover, to ease the need for a trusted third auditor in traditional data public auditing schemes, we introduce blockchain technique to enable a distributed data public auditing. In addition, with the group signature, our scheme also realizes anonymity and traitor tracing. The security analysis and performance evaluation show that our scheme is practical for large-scale IoT systems.

中文翻译：

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物联网中多个组的基于区块链的细粒度数据共享

如今，基于云的物联网被认为是有前途的范例，它可以为我们的社会提供各种应用程序。但是，随着物联网设备中的大量敏感和私有数据被收集并外包到云中以进行数据存储，处理或共享以节省成本，数据安全已成为其进一步发展的瓶颈。此外，在许多大型物联网系统中，多组数据共享对于用户而言是切实可行的。因此，如何确保多组数据共享中的数据安全仍然是一个悬而未决的问题，尤其是细粒度的访问控制和通过公共审核进行的数据完整性验证。因此，在本文中，我们为基于云的IoT系统中的多个组提出了一种基于区块链的细粒度数据共享方案。特别是，我们设计了一种新颖的多权限大型Universe CP-ABE方案，通过将组签名集成到我们的方案中来确保跨多个组的细粒度访问控制和数据完整性。此外，为了减轻传统数据公开审计方案中对可信任的第三审计员的需求，我们引入了区块链技术以实现分布式数据公开审计。此外，通过组签名，我们的方案还实现了匿名和叛徒追踪。安全性分析和性能评估表明，我们的方案适用于大规模物联网系统。我们引入了区块链技术以实现分布式数据公共审计。此外，通过组签名，我们的方案还实现了匿名和叛徒追踪。安全性分析和性能评估表明，我们的方案适用于大规模物联网系统。我们引入了区块链技术以实现分布式数据公共审计。此外，借助组签名，我们的方案还实现了匿名性和叛徒追踪。安全性分析和性能评估表明，我们的方案适用于大规模物联网系统。