In MANET maintaining the confidentiality and integrity of information is a challenging task due to its fundamental characteristic like open shared wireless medium, absence of central controller, limited bandwidth, physical vulnerabilities, limited processing power and limited battery power of devices, etc. In this paper, we introduce a security enhanced Zone Routing Protocol (SEZRP). The proposed method used the authentication technique to secure the routing packet in ZRP and efficiently prevent most frequently occurred attacks. Message Authentication Code (MAC) is used for maintaining the confidentiality of the messages. The key pre-distribution technique is also used in proposed method to minimize the overhead caused by distributing and sharing the keys at the run time. Network Simulator tool NS2.35 is used for simulation. Simulation result shows the performance comparison of SEZRP and ZRP routing protocol in the presence and absence of malicious nodes.