Wireless sensor networks (WSNs) have become a cornerstone of modern monitoring systems due to their wide-ranging applications in environmental observation, industrial automation, and military operations. Despite their growing importance, these networks face two persistent challenges: maximizing network lifetime and ensuring robust security against threats, particularly distributed denial-of-service (DDoS) attacks, which can severely disrupt operations. This research introduces the MITDCPS protocol as a novel solution addressing both energy efficiency and security simultaneously. MITDCPS operates by intelligently balancing cluster sizes and optimizing intra-cluster transmission distances, which significantly reduces energy consumption and prolongs the network’s operational life. The protocol’s structure comprises four systematically designed stages that manage clusters efficiently while minimizing intra-cluster communication distances. Beyond energy optimization, MITDCPS incorporates a security mechanism capable of identifying abnormal traffic patterns and isolating malicious nodes, thereby providing effective resistance against DDoS attacks. Experimental results indicate that MITDCPS not only enhances energy efficiency but also substantially strengthens network security, creating a stable and reliable environment for critical WSN applications. By integrating energy management with threat mitigation, MITDCPS offers a comprehensive framework that ensures both longevity and protection, highlighting its potential as a practical approach for real-world wireless sensor network deployments. Overall, this study demonstrates that careful cluster management and proactive security measures can coexist in a single protocol, addressing two of the most pressing challenges in the field.