Cryptanalysis and improvement of 'an improved authentication with key agreement scheme on elliptic curve cryptosystem for global mobility networks'

Authentication schemes assure that authorised user can fraudulently obtain his/her required services from home domains. Recently, Li et al. (International Journal of Network Management, 2013; 23(5):311-324) proposed a remote user authentication scheme. They claimed that their protocol is secure against known security attacks. However, in this paper, we indicate that Li et al.'s scheme is insecure against user impersonation attack. We show that an active adversary can easily masquerade as a legitimate user without knowing the user's secret information. As a remedy, we also proposed an improved authentication scheme to overcome the security weaknesses of Li et al.'s scheme. To show the security of our scheme, we prove its security the random oracle model. The implementation results show that our improved scheme offers a reduction of 58% in computational cost and a communication cost reduction of 48% with respect to Li et al.'s scheme. Copyright (c) 2014 John Wiley & Sons, Ltd.