Recent research in secure routing for wireless sensor networks focuses on developing intelligent and adaptive protocols that ensure reliable data transmission while defending against threats such as sinkhole, wormhole, and Sybil attacks. Modern approaches integrate trust-based mechanisms, cryptographic techniques, and machine learning models to dynamically assess node behavior and select secure communication paths. Blockchain-assisted routing and lightweight encryption methods are increasingly employed to enhance data integrity and authentication without excessive energy consumption. These innovations aim to balance energy efficiency, latency, and network security, ensuring robust and trustworthy routing in resource-constrained and mission-critical WSN environments.