Mobile ad hoc networks (MANETs) represent collaborative networks formed by mobile nodes without a centralized infrastructure, finding application across diverse domains including military and security-sensitive operations. However, securing the routing process within MANETs poses significant challenges due to the absence of a central authority and the dynamic nature of the network. Existing routing protocols suffer from limitations such as bandwidth consumption and route request delays. In response, this paper introduces the Secure and Energy-efficient Zone-based Multipath Routing Protocol (SEZMRPR) for MANETs. SEZMRPR integrates proactive and reactive approaches while incorporating digital signatures and encryption techniques to ensure message integrity, data confidentiality, and end-to-end authentication at the IP layer. The paper provides a comprehensive design of SEZMRPR, assesses its resilience against security attacks, and evaluates its performance through simulations. Results demonstrate SEZMRPR's robustness against security threats, its efficient security performance with acceptable overhead, and its applicability in securing MANETs for military and security-sensitive operations. SEZMRPR, in conjunction with existing security measures, establishes a reliable framework for ensuring secure operations in ad hoc networks. Future enhancements may focus on optimizing performance, scalability, energy efficiency, and addressing quality of service requirements to further refine the protocol.