Privacy-Preserving Energy-Aware Routing for Partially Sustainable IoT Networks in Smart Cities

Smart-city wireless sensor and Internet of Things (IoT) networks are progressively transitioning toward sustainable energy sources. During this transition, rechargeable energy-harvesting nodes must coexist with conventional devices powered by non-rechargeable batteries, creating partially sustainable IoT networks with conflicting energy-management objectives. Energy-harvesting nodes seek energy-neutral operation, whereas conventional nodes must minimize consumption to extend their operational lifetime. Coordinating these devices requires the exchange of energy information (EI), particularly battery state of charge. However, disclosing such information can enable adversaries to identify energy-constrained nodes and target them through energy-depletion attacks. This study examines the existing Dual Energy PROfile for interNet-of-thiNgs with Enhanced Security (DEPRONN-ES) framework for heterogeneous smart-city IoT networks. The framework integrates dual-profile energy management, energy-aware routing, adaptive data aggregation, and differential privacy. The focus is their coordinated application to heterogeneous energy resources and privacy-preserving EI exchange, rather than the introduction of new individual techniques. The framework was implemented using Contiki-NG and evaluated through Renode emulation with real indoor light-intensity traces from Columbia University to model energy harvesting by rechargeable nodes. The results show that, with a privacy budget of 0.1, DEPRONN-ES reduces the attacker’s target-identification success rate from 100% to 13.33%, representing an 86.67-percentage-point reduction. This reduction concerns targeting accuracy and does not imply prevention of malicious traffic. It also enables sustainable and conventional nodes to operate according to their distinct energy objectives. The reported findings suggest potential benefits from coordinating privacy protection and energy management under the evaluated conditions.