The Internet of Things (IoT) has been evolving for more than a decade. Technological advancements have increased its popularity, but concerns and risks related to IoT are growing considerably along with the increased number of connected devices. In 2013, a new cryptography-based infrastructure called blockchain emerged with the potential to replace the existing cloud-based infrastructure of IoT through decentralization. In this article, we provide a taxonomy of the challenges in the current IoT infrastructure, and a literature survey with a taxonomy of the issues to expect in the future of the IoT after adopting blockchain as an infrastructure. The two architectures are compared based on their strengths and weaknesses. Then a brief survey of ongoing key research activities in blockchain is presented, which will have considerable impact on overcoming the challenges encountered in the applicability of blockchain in IoT. Finally, considering the challenges and issues in both infrastructures and the latest research activities, we propose a high-level hybrid IoT approach that uses the cloud, edge/fog, and blockchain together to avoid the limitations of each infrastructure.

物联网（IoT）已经发展了十多年。技术进步已使其普及，但是随着连接设备数量的增加，与物联网相关的担忧和风险也大大增加。2013年，出现了一种新的基于密码学的基础架构，称为区块链，有潜力通过分散化来取代现有的基于云的物联网基础架构。在本文中，我们提供了当前物联网基础设施面临的挑战的分类法，并提供了一份文献调查，其中对采用区块链作为基础设施后物联网未来的预期问题进行了分类。根据两种架构的优缺点进行比较。然后简要介绍了区块链中正在进行的关键研究活动，这将对克服区块链在物联网中的适用性所遇到的挑战产生巨大影响。最后，考虑到基础架构和最新研究活动中的挑战和问题，我们提出了一种高级混合物联网方法，该方法结合使用云，边缘/雾和区块链来避免每个基础架构的局限性。