This paper deals with key establishment protocol needed prior to cryptographic communication. First, the existing key establishment protocols are classified according to key control, cryptographic techniques used, trusted third party, time-variant parameters and the number of passes. And then their properties are compared in four groups; key transport protocols on symmetric techniques, key transport protocols on asymmetric techniques, key agreement protocols on symmetric techniques, and key agreement protocols on asymmetric techniques.
Next, new key agreement protocols are proposed, which are based on Diffie-Hellman problem and is working over elliptic curve group in the setting of asymmetric techniques. Three proposed protocols are the followings; Protocol 4 is an AK( Authenticated Key agreement) protocol, Protocol 5 is an AKC (Authenticated Key agreement with key Confirmation) protocol, and Protocol 6 is an unilateral AKC protocol. And then these protocols are compared with the related work(i.e.the MTI/AO,Unified Model, MQV, and Protocol IIA) in security and performance.