Several practical protocols for authentication and key exchange

Ueli M. Maurer, Björn Tackmann, Sandro Coretti

Key exchange with unilateral authentication (short: unilateral key exchange) is an important primitive in practical security protocols; a prime example is the widely deployed TLS protocol, which is usually run in this mode. Unilateral key-exchange protocols are employed in a clientserver setting where only the server has a certified public key. The client is then authenticated by sending credentials via a connection that is secured with the key obtained from the protocol. Somewhat surprisingly and despite its importance in practical scenarios, this type of key exchange has received relatively little attention in the cryptographic literature compared to the type with mutual authentication. In this work, we follow the constructive cryptography paradigm of Maurer and Renner (ICS 2011) to obtain a (composable) security definition for key-exchange protocols with unilateral authentication: We describe a “unilateral key ” resource and require from a key-exchange protocol that it constructs this resource in a scenario where only the server is authenticated. One main advantage of this approach is that it comes with strong composition guarantees: Any higher-level protocol proven secure with respect to the unilateral key resource remains secure if the key is obtained

Colin Boyd, Anish Mathuria

Mihir Bellare Y, Ran Canetti, Hugo Krawczyk

We present a general framework for constructing and analyzing authentication protocols in realistic models of communication networks. This framework provides a sound formalization for the authentication problem and suggests simple and attractive design principles for general authentication and key exchange protocols. The key element in our approach is a modular treatment of the authentication problem in cryptographic protocols; this applies to the definition of security, to the design of the protocols, and to their analysis. In particular, following this modular approach, we show how to systematically transform solutions that work in a model of idealized authenticated communications into solutions that are secure in the realistic setting of communication channels controlled by an active adversary. Using these principles we construct and prove the security of simple and practical authentication and key-exchange protocols. In particular, we provide a security analysis of some well-known key exchange protocols (e.g. authenticated Diffie-Hellman key exchange), and of some of the techniques underlying the design of several authentication protocols that are currently being

Colin Boyd, Wenbo Mao

Whitfield Diffie, Paul C. van Oorschot, Michael J. Wiener

Mingping Qi, Jianhua Chen

Authenticated key exchange (AKE) is a crucial cryptographic primitive used for establishing an authenticated and confidential communication channel between parties, which has been widely used in our daily life when we surf on the Internet. However, in past decades mutual AKE protocols have been studied extensively in theory, while in many practical environments such as in the Tor anonymity network the mutual authentication property is undesirable. Meanwhile, considering privacy protection is getting more and more attention and one-way AKE protocols play an important role in privacy protection, so no matter in theory or in practice, it is quite meaningful to conduct research on the one-way AKE protocols. In this article, we present a new efficient anonymous one-way AKE protocol, which has strong anonymity and security properties guarantee, and efficiency advantages. Moreover, our new scheme has tight security reduction and is formally proved secure in the random oracle model under the Gap-DH and XCR signature security assumptions.