The most important phase to established communication between mobile station and base station is the Initial Network Entry Process. This process has vulnerabilities against malicious attacks that affect communication efficiency. Although several Initial Network Entry protocols are proposed, however most of them suffer from several weaknesses like vulnerabilities to varied attacks, low communication efficiency with using a high complexity of protocol structure. In order to overcome these shortcomings, we propose astrong mechanism and new method of authentication scheme using the elliptic curve digital signature algorithm. The proposed security protocol, named ESINEP “An Efficient and Secure Initial Network Entry Protocol”, used to share a secure key between mobile station and base station to authenticate each other and to secure communication. While designing ESINEP our main aims are assure: message integrity, source authentication, low communication cost, the fast verification and efficient exchange of messages. Finally, a formal security verification using Scyther tools concludes that ESINEP is secure against the existing attacks.