Abstract

The emergence of smart cities has transformed urban living through the integration of big data and IoT technologies. While these advancements enhance service delivery and infrastructure efficiency in areas like traffic management, healthcare, and public safety, they also raise significant concerns about data security and privacy. This chapter explores the role of cryptographic technologies in securing the vast amounts of sensitive information generated by smart city systems. It discusses encryption, digital signatures, blockchain, and their applications in maintaining data integrity, confidentiality, and access control. Special attention is given to securing IoT devices, which are integral to smart city frameworks but pose unique vulnerabilities. Real-world case studies illustrate the use of blockchain for transparency and end-to-end encryption for personal data protection. The chapter also addresses the growing relevance of quantum-resistant cryptography, proposing a unified security framework for future smart cities to ensure resilience, privacy, and trust.