Security analysis of IKE’s signature-based key-exchange protocol

Abstract

We present a security analysis of the Diffie-Hellman keyexchange protocol authenticated with digital signatures used by the Internet Key Exchange (IKE) standard. The analysis is based on an adaptation of the key-exchange model from [Canetti and Krawczyk, Eurocrypt’ 01] to the setting where peers identities are not necessarily known or disclosed from the start of the protocol. This is a common practical setting, including the case of IKE and other protocols that provide confidentiality of identities over the network. The formal study of this “post-specified peer” model is a further contribution of this paper.