Abstract: Key agreement is an important mean to realize the secure communication between participants under the open and fair environment.This paper proposed a novel three-party key agreement protocol which has the sender authentication property.We used a one-way isomorphism to generate session key.And this mean avoids the insecurity of Hash function.We then gave the rigid security proof for our new protocol and compared the computational cost with some refe-rences.The result shows that our protocol has known key security,perfect forward security and can resist on the key compromise impersonation attack,and our protocol also has the acceptable computational cost.

Key words: Cryptography,Key agreement,One-way isomorphism,Cryptanalysis,Standard model