Trust aware secure energy-efficient routing protocol for clustered wireless sensor networks using two-tier optimization algorithm

Background Wireless sensor networks (WSNs) consist of numerous small, low-cost, and low-power sensor nodes. These nodes collect data from their environment and transmit it to a base station either directly (single-hop) or through other nodes (multi-hop). To ensure secure and reliable operation, cryptographic approaches have traditionally been used to defend against external threats. However, internal threats such as badmouth and on–off attacks remain challenging. Trust-based mechanisms have been proposed to address these threats by evaluating node behavior based on past interactions, but such mechanisms are still vulnerable to manipulation, sometimes causing normal nodes to be misclassified as malicious. Methods This study proposes a Trust Aware Secure Energy-Efficient Routing Protocol for Clustered Wireless Sensor Networks using a Two-Tier Optimization approach (TSEERPC-TTO). The framework operates in two stages. First, the Improved Sparrow Search Algorithm (ISPSA) is used for efficient clustering of sensor nodes to optimize resource usage and energy consumption. Second, the Harris Hawks Optimizer (HHO) ensures secure and reliable routing of data. A key innovation of the model is the integration of a trust factor into the routing fitness function, which progresses resilience against malicious nodes and strengthens network security. Results Simulation results on large-scale deployments (500 nodes) found that the proposed TSEERPC-TTO provocatively outperforms existing protocols. Accurately, it develops a packet delivery ratio to 98.6% under blackhole attacks ( vs . 93.0–97.9% in benchmarks), reduces average energy consumption to 0.12 mJ under 10 malicious nodes ( vs . 0.16–0.27 mJ), and lowers detection speed to 1.93 rounds related to 1.96–6.02 in baseline models. Additionally, the model maintains higher trust factor stability and resilience against selective forwarding, achieving up to 98.1% PDR with malicious nodes while extending network lifetime.