Identity-based authenticated key agreement protocols in multiple PKG environments in the standard model

Most available identity-based authenticated key agreement protocols require that both protocol participants are from the same PKG environment, which are unfit for roaming between different domains and the asymmetric computational environment in heterogeneous integrated network. So it is quite needed to propose identity-based authenticated key agreement protocol in multiple PKG environments. This paper presents an identity-based authenticated key agreement protocol in multiple PKG environments in standard model, which is an improved version of recent proposed protocol. The intruder's ability is improved to issue one PKG's master private key in ID-BJM model for multiple PKG environments. The new protocol is proved secure in improved ID-BJM model.