An Improvement to Lee and Hwang´s Scheme

There are many key agreement schemes or key exchange schemes to help two parties to allow both parties computing a common session key in a public network. However, some of schemes can result these two parties compute no common session key. for instance, in 2010, Lee and Hwang proposed such a key exchange scheme that has a chance to make two protocol parties to compute no common session key. in this paper, we will improve it.