Security has become a primary concern to provide protected communication in wireless networks. The primary aim of this book is to explore the performance advantages obtained by securing wireless networks using ECC in lieu of the traditional RSA. To begin with, the performance advantages of ECC over prime fields were analyzed by implementing it in the Handshake Protocol for Secure Sockets Layer (SSL). Exploiting the advantages of ECC over binary fields, a mutual authentication and session key management protocol for Mobile Ad hoc Networks has been developed. A high speed and less complex ECC algorithm over binary fields using a new Ring representation technique has been developed. Further, the developed high speed and less complex ECC algorithm over binary fields has been implemented for securing wireless sensor networks.