Continuous After-the-Fact Leakage-Resilient Key Exchange

Both mutual authentication and generation of session keys can be accomplished by an authenticated key exchange (AKE) protocol. Let us consider the following situation: (1) a client, who communicates with many different servers, remembers only one password and has insecure devices (e.g., mobile phones or PDAs) with very-restricted computing power and built-in memory capacity; (2) the counterpart servers have enormous computing power, but they are not perfectly secure against various attacks (e.g., virus or hackers); (3) neither PKI (Public Key Infrastructures) nor TRM (Tamper-Resistant Modules) is available. The main goal of this paper is to provide security against the leakage of stored secrets as well as to attain high efficiency on client's side. For those, we propose an efficient and leakage-resilient RSA-based AKE (RSA-AKE) protocol suitable for the above situation whose authenticity is based on password and another secret. In the extended model where an adversary is given access to the stored secret of client, we prove that its security of the RSA-AKE protocol is reduced tightly to the RSA one-wayness in the random oracle model. We also show that the RSA-AKE protocol guarantees several security properties (e.g., security of password, multiple sever scenario with only one password, perfect forward secrecy and anonymity). To our best knowledge, the RSA-AKE protocol is the most efficient, in terms of both computation costs of client and communication costs, over the previous AKE protocols of their kind (using password and RSA).

A two-party authenticated key exchange (AKE) protocol allows each of the two parties to share a common secret key over insecure channels, even in the presence of active adversaries who can actively control and modify the exchanged messages. To capture the malicious behaviors of the adversaries, there have been many efforts to define security models. Amongst them, the extended Canetti–Krawczyk (eCK) security model is considered one of the strongest security models and has been widely adopted. In this paper, we present a simple construction of a pairing-based eCK-secure AKE protocol in the standard model. Our protocol can be instantiated with a suitable signature scheme (i.e., an existentially unforgeable signature scheme against adaptive chosen message attacks). The underlying assumptions of our construction are the decisional bilinear Diffie–Hellman assumption and the existence of a pseudorandom function. Note that the previous eCK-secure protocol constructions either relied on random oracles for their security or used somewhat strong assumptions, such as the existence of strong-pseudorandom functions, target collision-resistant functions, etc., while our protocol construction uses fewer and more-standard assumptions in the standard model. Furthermore, preserving the same security argument, our protocol can be instantiated with any appropriate signature scheme that comes in the future with better efficiency.

This chapter explains the elements of key exchange, specifically the steps in a key exchange protocol, the parties that are involved and the messages which may be sent. It details key exchange security models and protocols, considering first the simpler case of unauthenticated key exchange before turning to authenticated protocols. The chapter deals with key exchange protocols designed to be secure against a passive adversary. It examines that unauthenticated protocols may be used as building blocks for authenticated key exchange protocols. Key exchange protocols that allow parties to verify the identity of other participating parties are called authenticated key exchange protocols. Key exchange has a long history and a vast literature, yet remains a very active research area with significant practical impact. It is inevitable that as new computational assumptions emerge as the basis for cryptographic security, so will their use in key exchange be relevant.

Security issues play an important role in modern communication worlds. Via distrusted networks, exchanged messages need to be encrypted by a session key for security requirements. Session keys are preferred to be generated by communication parties, and how to authenticate the other communication party is an important problem needed to be solved. In three-party encrypted key exchange (3PEKE) protocols, a special type of indirect-authenticated protocols, a trusted third party is involved to have two communication parties be able to authenticate each other and negotiate one session key. In 2008, Yoon and Yoo proposed a three-party encrypted key exchange protocol and claimed their protocol provides a more secure way for exchanging messages. Unfortunately, we find that their protocol suffers from undetectable one-line password guessing attacks. In this manuscript, we first review the important related works and show how to mount attacks on Yoon and Yoo’s 3PEKE protocol

Establishing a session key (SSK) is very important for real-world deployment in open networks, which enables secure communication between remote parties. In the past, some authenticated key exchange (AKE) protocols have been proposed to generate a SSK, but the certificate management issue is inhered in the traditional public key infrastructure and must be addressed. To tackle this issue, the identity (ID)-based concept is added to AKE, called ID-AKE. Indeed, the security of the existing AKE/ID-AKE protocols is gaining increasing importance due to some new types of attacks, namely, side-channel attacks. In such attacks, adversaries could obtain secret keys’ partial information during the execution of cryptographic protocols (including AKE/ID-AKE). To withstand such attacks, many leakage-resilient ID-AKE (LR-ID-AKE) protocols resisting side-channel attacks have been proposed. However, these existing LR-ID-AKE protocols have no efficient solution to revoke compromised users. In this article, the first LR-ID-AKE protocol with an efficient revocation mechanism, called LR-RID-AKE, is proposed. The proposed protocol is not only as secure as existing LR-ID-AKE protocols but also able to efficiently revoke compromised users from the system.

Recent work by Krawczyk [12] and Menezes [16] has highlighted the importance of understanding well the guarantees and limitations of formal security models when using them to prove the security of protocols. In this paper we focus on security models for authenticated key exchange (AKE) protocols. We observe that there are several classes of attacks on AKE protocols that lie outside the scope of the Canetti-Krawczyk model. Some of these additional attacks have already been considered by Krawczyk [12]. In an attempt to bring these attacks within the scope of the security model we extend the Canetti-Krawczyk model for AKE security by providing significantly greater powers to the adversary. Our contribution is a more compact, integrated, and comprehensive formulation of the security model. We then introduce a new AKE protocol called NAXOS and prove that it is secure against these stronger adversaries.

In three-party password authenticated key exchange (AKE) protocol, since two users use their passwords to establish a secure session key over an insecure communication channel with the help of the trusted server, such a protocol may suffer the password guessing attacks and the server has to maintain the password table. To eliminate the shortages of password-based AKE protocol, very recently, according to chaotic maps, Lee et al. [2015 Nonlinear Dyn. 79 2485] proposed a first three-party-authenticated key exchange scheme without using passwords, and claimed its security by providing a well-organized BAN logic test. Unfortunately, their protocol cannot resist impersonation attack, which is demonstrated in the present paper. To overcome their security weakness, by using chaotic maps, we propose a biometrics-based anonymous three-party AKE protocol with the same advantages. Further, we use the pi calculus-based formal verification tool ProVerif to show that our AKE protocol achieves authentication, security and anonymity, and an acceptable efficiency.

The Key-exchange protocol is one of the most basic and widely used cryptographic protocols in internet for secure communication. In a two-party setting, cryptographic protocol design has often ignored the possibility of simultaneous message transmission by each of the two parties. Most protocols for two-party have been designed assuming that parties alternate sending their messages. We present two provably-secure protocols for two-party authenticated key exchange (AKE) which require not only a single round, but more efficient message transmission (from a computational perspective). The protocol provides Implicit Authentication, key independence and forward secrecy , and is analyzed in the standard model. The protocols are the first provably-secure one-round protocol for authenticated 2-party key exchange in the standard model that the message lengths are equal to the basic protocol.

The key exchange protocol is the most important cryptography mechanism to protect end-to-end communications by the secret session key encryption. This paper focuses on the four-party key exchange protocol in a environment in which two clients (or UEs) are registered under two distinct servers. We propose a Three-Way Key Exchange and Agreement Protocol, denoted by TW-KEAP. It makes two communication parties have a secret session key to protect their subsequent communications on an efficient way, and intends the servers to involve with the key exchange procedure to derive the session key for the lawful interception support. Security analyses show that it provides mutual authentication, replay attack protection and perfect forward secrecy. Furthermore, the TW-KEAP has not only the shortest total service time based on the experimental results but also the shortest queuing delay from the queuing model analyses, as compared with current alternatives.

An authenticated group key exchange (AGKE) protocol allows participants to construct a common key and provide secure group communications in cooperative and distributed applications. Recently, Choi...

SUMMARYThis paper investigates authenticated key exchange (AKE) protocol under computational Diffie–Hellman assumption in the extended Canetti–Krawczyk model. The core technical component of our protocol is the trapdoor test technique, which is originally introduced to remove the gap Diffie–Hellman (GDH) assumption for the public key encryption schemes. Our contributions are twofold.First, we clarify some misunderstandings of the usage of the trapdoor test technique in AKE protocols showing its adaptation to the AKE protocols is not trivial. We point out some errors in some recent work which attempts to make use of the trapdoor test technique to remove GDH assumption.Second, based on trapdoor test technique, we propose an efficient extended Canetti–Krawczyk secure AKE protocol under computational Diffie–Hellman assumption instead of GDH assumption. Additionally, our protocol does not make use of NAXOS trick and has a tight reduction. In comparison with all existing AKE protocols with the properties as previously mentioned, our protocol with only three exponentiations is most efficient. Copyright © 2013 John Wiley & Sons, Ltd.

In 2003, Huang et al. proposed an authenticated key exchange (AKE) protocol for secure communications between a sensor and a security manager based on elliptic curve cryptography in a self-organizing sensor network. In 2005, Tian et al., however, showed that a security manager will learn the long-term private key of a sensor after having one normal run of the protocol with the sensor. Then they proposed an improvement which solves the problem. The current paper, however, demonstrates neither protocol provides perfect forward secrecy, and presents an improved protocol in order to address this problem. Not only is the computational cost of the proposed AKE protocol less than that of both protocols, the number of steps in communication is one fewer than conventional protocols and only needs three steps.KeywordsCryptographySensor networkKey exchange protocolSecure communicationSelf-organizing

In cryptography, the key exchange protocol is very important before starting secure communication. Both parties will use an asymmetric key algorithm to exchange their keys for encryption and decryption. One of the methods to securely exchange the keys is Diffie-Hellman Key Exchange (DHKE) protocol. DHKE allows both parties to exchange their keys over the insecure public channel safely. However, DHKE protocol does not authenticate the message, making it easily exposed to third-party interruptions like Man-in-the-Middle (MitM) attack. Therefore, Station to Station (STS) protocols was introduced after modifying the DHKE protocol and adding authentication elements. Thus, this paper proposes to provide the authentication of the STS protocol by using Lamport Digital Signature Scheme. Lamport Digital Signature Scheme, also known as Lamport one-time signature scheme, gives very strong security because it can be built from any cryptographically secure one-way function and usually uses a cryptographic hash function. The results from the study are STS protocol algorithms that provide a verification scheme using the Lamport Digital Signature Scheme. As a result, both parties will obtain a common key for encryption and decryption, in which both parties play a role by using their respective digital signature for verification within the STS of this protocol

Authentication is an effective mechanism for determining whether a user is unauthorized to access to the device and/or online account. In addition, users may also be concerned about preserving their online privacy (e.g. identity, and individual preferences). Conventional anonymous two-factor authenticated key exchange (AKE) protocols only guarantee user anonymity against an external adversary, although user identity may be easily learned by a malicious insider (e.g. server), and the latter may also trace the user’s activities and analyze the user’s individual preferences for illicit financial gains. To address this problem, we propose a novel anonymous two-factor AKE protocol, which achieves stronger anonymity in the sense that no useful information about the user’s identity is revealed to either an adversary or the server. We then give a formal security proof of the protocol in the random oracle model.

A Lightweight Leakage-Resilient Identity-Based Mutual Authentication and Key Exchange Protocol for Resource-limited Devices