A vision of blockchain technology and its integration with iot: applications, challenges, and opportunities; from the authentication perspective

The Internet of Things (IoT) is used in our daily lives, thus this type of technology greatly affects various environments such as smart home, smart cities, and industrial systems. Through IoT, daily objects will be able to interact and interconnect to gather information and automate specific tasks. An IoT framework is a group of guiding rules, protocols, and standards. The implementation of IoT applications depends on the characteristics of the IoT environment especially the security issue and the mechanisms implemented for this purpose, where security and privacy are pivotal. This paper maps the research landscape in two ways. The first describes the blockchain technology, the principles of using the blockchain technology, and the different areas of its applications. The second highlights the capabilities and challenges of blockchain, the most famous applications of IoT used in blockchain, and the opportunities of using blockchain together with IoT in the present and future. Finally, the recommendations and future research directions are discussed.