Abstract
In recent years, unprecedented work has been done in the area of smart cities. The purpose of developing smart cities is to enhance quality of life factors for people dwelling within them. To achieve that purpose, technologies such as IoT and cloud computing have been utilized. Blockchain technology is also among the promising technologies that can offer countless valuable services to its end users. It is a immutable programmable digital register for the purpose of recording virtual assets having some value and was primarily developed for digital currencies like Bitcoin. To fully utilize the services of blockchain technology within smart cities, characteristics of blockchain technology, and its key requirements and research challenges need to be identified. Hence, in this article, an attempt has been made to identify the characteristics of blockchain technology. Furthermore, indispensable requirements for incorporating blockchain technology within smart cities are enumerated. A conceptual architecture for securing smart city using blockchain technology is proposed and explained using a possible use case study. An overview of a real-world three-blockchain- based smart city case study is also presented. Finally, several imperative research challenges are identified and discussed.