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Authenticated key exchange protocols represent an important cryptographic mechanism that enables several parties to communicate securely over an open network. Elashry, Mu, and Susilo proposed an identity-based authenticated key exchange (IBAKE) protocol where different parties establish secure communication by means of their public identities.The authors also introduced a new security notion for IBAKE protocols called resiliency, that is, if the secret shared key is compromised, the entities can generate another shared secret key without establishing a new session between them. They then claimed that their IBAKE protocol satisfies this security notion. We analyze the security of their protocol and prove that it has a major security flaw, which renders it insecure against an impersonation attack. We also disprove the resiliency property of their scheme by proposing an attack where an adversary can compute any shared secret key if just one secret bit is leaked. [ABSTRACT FROM AUTHOR]

In this paper, the random access procedure of Universal Mobile Telecommunications System network is investigated. We have proposed a model based on communicating timed automata that represents the main functions related to the random access procedure including the user equipment, the base station (node B or BTS), and the channel. Then, we have used computational tree logic formula to specify the proprieties to be verified. The model and the formulas serve as inputs to the model checker, which is used as a verification engine, ie, UPPAAL and SPIN. The formal verification approach shows that the protocol has several drawbacks that may not be detected by simulation. [ABSTRACT FROM AUTHOR]

Authentication schemes have been widely deployed access control and mobility management in various communication networks. Especially, the schemes that are based on multifactor authentication such as on password and smart card come to be more practical. One of the standard authentication schemes that have been widely used for secure communication over the Internet is session initiation protocol (SIP). The original authentication scheme proposed for SIP was vulnerable to some crucial security weaknesses. To overcome the security problems, various improved authentication schemes have been developed, especially based on elliptic curve cryptography (ECC). Very recently, Zhang et al. proposed an improved authentication scheme for SIP based on ECC using smart cards to overcome the security flaws of the related protocols. Zhang et al. claimed that their protocol is secure against all known security attacks. However, this paper indicates that Zhang et al. protocol is still insecure against impersonation attack. We show that an active attacker can easily masquerade as a legal server to fool users. As a remedy, we also improve Zhang et al. protocol by imposing a little extra computation cost. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The SMEN protocol, proposed by Wu and Ustaoglu in 2009, has been considered to be secure as the authors claimed, and numerous theories are proposed based on this protocol. This paper analyzes the SMEN protocol and finds that this protocol is not resistant to the session corruption attack and the key compromise impersonation attack. Then, we propose an improved protocol with tight security reduction. Our improved protocol not only avoids the above attacks but also embraces the same efficiency as the SMEN protocol in terms of exponentiation. Besides, formal analysis of the improved protocol is presented by using the formal automatic security analysis tool Scyther. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Summary: In this, we propose a generalized partial relay selection (PRS) protocol to enhance the secrecy performance for cooperative cognitive radio networks (CRNs) in terms of the secrecy outage probability (SOP) and the probability of non‐zero secrecy capacity (NSC). In the proposed scheme, a secondary source communicates with a secondary destination via the assistance of multiple secondary relays, in the presence of multiple secondary eavesdroppers and multiple primary users (PUs). With a reliance on the source‐relay channel state information (CSI), the source selects a group of the potential relays, and one is then chosen to forward the source data to the secondary destination using the randomize‐and‐forward (RF) technique. We consider the relay selection methods in two practical cases, where the CSIs of the eavesdropping links are available or not available. For the performance evaluation and comparison, we derived exact and asymptotic SOP and NSC closed‐form expressions for the proposed protocols and the corresponding full relay selection (FRS) protocol over Rayleigh‐fading channels. Finally, Monte Carlo simulations are presented to confirm the theoretical‐derivation correction. The results confirmed that the proposed protocols can outperform the conventional PRS protocols by designing the number of the potential relays appropriately. We propose a generalized partial relay selection (PRS) protocol to enhance the secrecy performance for cooperative cognitive radio networks (CRNs) in terms of the secrecy outage probability (SOP) and the probability of non‐zero secrecy capacity (NSC). [ABSTRACT FROM AUTHOR]