With rapid development of enabling technologies such as Internet of Things, robotics, and big data, the fourth industrial revolution known as “Industry 4.0” (I4.0) has become a great opportunity for productivity innovation around the world. Industrial Internet of Things (IIoT), as a typical implication of Cyber-Physical Systems (CPS) in I4.0 era, has attracted significant attention. It aims at optimizing resources and improving production efficiency for manufacturing industry through deep interconnection of physical equipment, wide collection of multi-dimensional data, intelligent awareness of environment and automatic control. Blockchain is a kind of distributed ledger technology and has features including decentralization, anti-tamper, transparency, anonymity, and contract-autonomy. These features are helpful to improve the services and promote the development of IIoT. In this paper, we provide a comprehensive survey on the literatures applying blockchain technology into IIoT. We firstly introduce the related works and background knowledge. And then, the motivations and benefits for applying blockchain into IIoT are discussed in detail. Furthermore, based on the layered architecture of blockchain we summarized in the previous work, we outline the research framework of blockchain in IIoT. Meanwhile, the related application research is presented from the perspectives of devices security, data collection and sharing, and industrial application. Moreover, we explore the technical requirements of blockchain platforms in IIoT applications. Finally, some challenges and future directions on blockchain in IIoT, as well as broader perspectives, are concluded for further study.

中文翻译：

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工业物联网区块链综合调查：动机、研究进展和未来挑战


随着物联网、机器人、大数据等使能技术快速发展，被称为“工业4.0”（I4.0）的第四次工业革命成为全球生产力创新的重大机遇。工业物联网（IIoT）作为I4.0时代信息物理系统（CPS）的典型含义，备受关注。旨在通过物理设备的深度互联、多维数据的广泛采集、环境的智能感知和自动控制，为制造业优化资源、提高生产效率。区块链是一种分布式账本技术，具有去中心化、防篡改、透明、匿名、合约自治等特点。这些功能有助于完善服务，促进工业物联网的发展。在本文中，我们对将区块链技术应用于工业物联网的文献进行了全面的调查。我们首先介绍相关工作和背景知识。然后，详细讨论了将区块链应用于工业物联网的动机和好处。此外，基于我们在之前的工作中总结的区块链分层架构，我们概述了区块链在工业物联网中的研究框架。同时，从设备安全、数据采集与共享、行业应用等角度进行了相关应用研究。此外，我们还探讨了工业物联网应用中区块链平台的技术要求。最后，总结了工业物联网中区块链的一些挑战和未来方向，以及更广泛的前景，以供进一步研究。