A Comprehensive Survey on Blockchain for Secure IoT- enabled Smart City beyond 5G: Approaches, Processes, Challenges, and Opportunities

Established and emerging technologies such as 5G, Internet of Things (IoT), and blockchain will play an increasingly significant role in smart city applications, which reinforce the importance of designing security and privacy-aware/preserving solutions. Hence, we comprehensively survey articles focusing on blockchain for a secure IoT-enabled smart city based on 5G and beyond, published between 2016 and 2023. In this survey, we first introduce the seminal contributions and background technological knowledge regarding smart city. Furthermore, based on the layered blockchain-based architecture of the IoT-enabled smart city, we provide an all-inclusive summary of previous works and outline the blockchain research framework in smart city. Then, we discuss how to use blockchain and beyond 5G in smart city applications, including smart manufacturing, and smart vehicular networks. In addition to reviewing the existing approaches described in the 125 articles surveyed, we also identify several limitations and present potential extensions to design future blockchainbased solutions for smart cities.