Mobile Ad Hoc Networks (MANETs) are dynamic, self-organizing networks that lack a fixed infrastructure, making them highly vulnerable to various security threats. One of the critical aspects in MANETs is the establishment of efficient and secure communication among mobile nodes. Routing protocols play a pivotal role in ensuring reliable data transmission in such environments. This paper presents a comprehensive overview of the challenges and solutions related to achieving secure and efficient communication within MANET routing protocols. The main objective of this paper is to define the path for security and to further improve throughput, routing overhead, end-to-end delay, packet delivery ratio, and at the same time to create an energy-enhanced way with excellent security. Implementation of cryptographic algorithms for the information is done in such a way that it is impossible for attackers to compromise the resources of information sent over the web. This paper proposes a new intrusion detection system called Enhanced Adaptive 3 Acknowledgement (ECC-EA3ACK), using EA3ACK with Elliptical Curve Cryptography (ECC) specially designed for MANETs. In this ECC, there is a two-key encryption technique based on elliptic curve theory that can be used to create faster, smaller, more energy-efficient cryptography. The above-developed on-demand routing protocol achieves better results than the existing model through one of the leading simulators called Network Simulator (NS2), which is used to implement and test the proposed system. The proposed cryptography provides secured transmission, reduces routing overhead, improves packet delivery ratio, throughput, and minimizes delay due to increased remaining energy and improved security.