Towards Resilient Smart Cities: Security, Trust, and Sustainability in Edge Computing - A Survey

Abstract

Edge computing has underpinned smart cities by enabling low-latency, localised intelligence for traffic, surveillance, and infrastructure. However, its decentralised, heterogeneous footprint poses severe risks to security, privacy, and environmental sustainability. This paper reviews secure, sustainable edge computing and introduces a unified framework balancing security with ecological constraints. It establishes a threat taxonomy covering expanded attack surfaces, identity flaws, and physical or AI-driven threats, then critically evaluates five core paradigms, AI anomaly detection, blockchain, secure virtualisation, and privacy analytics against latency and resource overhead. Crucially, we assess the environmental toll of these defenses using Energy per Operation (EPO), Energy-Delay Product (EDP), Carbon Intensity (CI), and Lifecycle Energy Use (LEU) metrics. Exposing a critical gap in the literature: the lack of standardised benchmarks for security carbon costs. Finally, we map future frontiers like post-quantum crypto, secure federated learning, digital twins, and edge-native zero-trust, proving that modern urban ecosystems must treat security and sustainability as co-dependent design requirements. The findings emphasise that future smart-city infrastructures must balance security, privacy, performance, and sustainability to achieve resilient and trustworthy edge computing ecosystems.