Abstract: | As the mobile network progresses fast, mobile communications have a far‐reaching influence in our daily life. In order to guarantee the communication security, a myriad of experts introduced many authentication protocols. Recently, Qi et al presented an enhanced authentication with key agreement protocol for satellite communications, and they proclaimed that their protocol could defend various attacks and support varied security requirements. Regrettably, in this paper, we prove that their protocol was fruitless in resisting smart card stolen or loss attack, supporting perfect forward secrecy and had a fundamental error. To solve these problems, we present an improved protocol based on perfect forward secrecy. In addition, the analysis of our improved protocol suggests that it gets possession of faultless security properties and overcomes the flaws in the protocol of Qi et al perfectly. Thus, our improved protocol can be appropriated for the mobile communications. |