The Convergence of Blockchain and <scp>IoT</scp> in Secure Smart Cities: A Survey of Applications, Challenges, and Opportunities

ABSTRACT Urbanization and population expansion have accelerated, highlighting the critical need for thoughtful, long‐term solutions to today's most important environmental and socioeconomic issues. In order to realize the vision of smart cities, this research investigates the revolutionary potential of incorporating blockchain technology and the Internet of Things (IoT) into numerous facets of urban life. Smart city programs seek to enhance resource efficiency, foster sustainability in critical domains, including healthcare, education, transportation, energy, and building management by utilizing sensor‐driven data and advanced analytics. In order to build blockchain‐enabled Internet of Things applications in smart cities, this paper lays out crucial goals, procedures, and elements. It highlights the importance of decentralized systems in lowering single points of failure and improving data integrity, security, and privacy. Personalized learning paths in education, real‐time patient monitoring in healthcare, effective transit networks, and dependable energy grids using renewable energy sources are a few examples of specific uses. The report also emphasizes how robust service delivery, smart contracts for process automation, and safe data interchange are made possible by blockchain and IoT integration. This study shows how decentralized blockchain solutions may greatly improve governance and operational resilience while also substantially contributing to the sustainable development of smart cities by resolving security and privacy.