A secure two-party key agreement protocol with key escrow and perfect forward secrecy

Abstract

To provide secure communications in open and distributed environments, authenticated key agreement protocol is an important primitive for establishing session key. So far, great deals of identity-based protocols have been proposed to provide robust mutual authentication and key establishment in two-party setting. Majority of the existing escrowable identitybased key agreement protocols, however, only provide partial forward secrecy. Therefore, such protocols are unsuitable for real-world applications that require a stronger sense of forward secrecy -- perfect forward secrecy. In this paper, we present a secure two-party identity-based authenticated key agreement protocol, which was inspired on an identity-based encryption scheme first proposed by Gentry (Eurocrypt'06). The proposed protocol achieves most of the required security attributes and can be used properly in the escrow mode. We show that the scheme achieves the attributes of known-key secrecy, key-compromise impersonation resilience, unknown key-share resilience and no key control. In addition, it captures the perfect forward secrecy attribute.