• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.12
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• pp.3366-3383
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• 2012

Reliance on the Internet has introduced Voice over Internet Protocol (VoIP) to various security threats. A reliable security protocol and an authentication scheme are thus required to prevent the aforementioned threats. However, an authentication scheme often demands additional cost and effort. Accordingly, a security framework for known participants in VoIP communication is proposed in this paper. The framework is known as Randomness-Optimized Self-Securing (ROSS), which performs authentication automatically throughout the session by optimizing the uniqueness and randomness of the communication itself. Elliptic Curve Diffie-Hellman (ECDH) key exchange and Salsa20 stream cipher are utilized in the framework correspondingly to secure the key agreement and the communication with low computational cost. Human intelligence supports ROSS authentication process to ensure participant authenticity and communication regularity. The results show that with marginal overhead, the proposed framework is able to secure VoIP communication by performing reliable authentication.

• Journal of the Korea Society of Computer and Information
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• v.17 no.4
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• pp.91-98
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• 2012

A group key exchange (GKE) protocol is designed to allow a group of parties communicating over a public network to establish a common secret key. As group-oriented applications gain popularity over the Internet, a number of GKE protocols have been suggested to provide those applications with a secure multicast channel. Among the many protocols is Yi et al.'s password-based GKE protocol in which each participant is assumed to hold their individual password registered with a trusted server. A fundamental requirement for password-based key exchange is security against off-line dictionary attacks. However, Yi et al.'s protocol fails to meet the requirement. In this paper, we report this security problem with Yi et al.'s protocol and show how to solve it.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4585-4602
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• 2016

A novel key sharing fuzzy vault scheme is proposed based on the classic fuzzy vault and the Diffie-Hellman key exchange protocol. In this proposed scheme, two users cooperatively build their fuzzy vault for their shared key using their own biometrics. Either of the users can use their own biometrics to unlock the fuzzy vault with the help of the other to get their shared key without risk of disclosure of their biometrics. Thus, they can unlock the fuzzy vault cooperatively. The security of our scheme is based on the security of the classic fuzzy vault scheme, one-way hash function and the discrete logarithm problem in a given finite group.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.10
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• pp.1786-1795
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• 2006

Portable Internet extended from wireless LAN has a large cell size, similar to a wireless mobile communication. and can provide the seamless service which offers middle-low speed mobility. IEEE 802.16e, the international standard of Portable Internet, uses PKMv2 protocol for authorization and key exchange between a MSS and a BS. This paper proposes a new protocol based on PKMv2, which can provide that MSS is able to do fast authorization with a new BS when soft handover is occurred in a MSS. Our protocol can carry out fast authorization because of reducing the number of messages and parameter exchange, public key encryption and signature in wireless network more than the previous works. It also prevents eavesdropping from an external attacker and keeps the security against impersonation attacks for both a MSS and a BS.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.872-875
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• 2005

Portable Internet extended from wireless LAN has a large cell size, similar to a wireless mobile communication, and can provides the seamless service which offers middle-low speed mobility. IEEE 802.16e, the international standard of Portable Internet, uses PKMv2(Privacy Key Management) protocol for authorization and key exchange between a MSS(Mobile Subscriber Station) and a BS(Base Station). This paper first reviews and studies overall security architecture of TTA HPi standard and IEEE 802.16e which supports mobility based on WMAN(Wireless Metropolitan Area Network) standard(IEEE 802.16)

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.12
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• pp.3018-3036
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• 2013

In this paper, we investigate power allocation scheme and outage performance for a physical-layer network coding (PNC) relay based secondary user (SU) communication in cognitive multi-antenna relay networks (CMRNs), in which two secondary transceivers exchange their information via a multi-antenna relay using PNC protocol. We propose an optimal energy-efficient power allocation (OE-PA) scheme to minimize total energy consumption per bit under the sum rate constraint and interference power threshold (IPT) constraints. A closed-form solution for optimal allocation of transmit power among the SU nodes, as well as the outage probability of the cognitive relay system, are then derived analytically and confirmed by numerical results. Numerical simulations demonstrate the PNC protocol has superiority in energy efficiency performance over conventional direct transmission protocol and Four-Time-Slot (4TS) Decode-and-Forward (DF) relay protocol, and the proposed system has the optimal outage performance when the relay is located at the center of two secondary transceivers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1518-1523
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• 2005

With the expansion of service over the internet, the recent network demands the amount of the more bandwidth and fast transfer rate. Optical Burst Switching has considered as a promising solution for supporting high-speed Internet Service. Because of OBS architecture, it has the security threats such as eavesdropping, masquerading, denial of service and so on. In this Paper, We analyze OBS-specific security threats and requirement for supporting security protocol n OBS networks. We propose an authentication and key exchange protocol for supporting the security service. This protocol supports explicit key authentication by using the control messages and protects the control message by using the session key.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4604-4623
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• 2014

Authentication mechanisms coupled with strong encryption techniques are used for network security purposes; however, given sufficient time, well-equipped intruders are successful for compromising system security. The authentication protocols often fail when they are analysed critically. Formal approaches have emerged to analyse protocol failures. In this study, Communicating Sequential Processes (CSP) which is an abstract language designed especially for the description of communication patterns is employed. Rank functions are also used for verification and analysis which are helpful to establish that some critical information is not available to the intruder. In order to establish this, by assigning a value or rank to each critical information, it is shown that all the critical information that can be generated within the network have a particular characterizing property. This paper presents an application of rank functions approach to an authentication protocol that combines delaying the decryption process with timed authentication while keys are dynamically renewed under pseudo-secure situations. The analysis and verification of authentication properties and results are presented and discussed.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.166-166
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• 2004

• Journal of the Korea Society of Computer and Information
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• v.10 no.3 s.35
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• pp.133-141
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• 2005

Digital contents can be distributed via internet without qualify defect and this will bring a great loss to the contents provider. Therefore, it is necessary to investigate on the key exchanging protocol to protect the digital contents effectively. In this study we propose the key exchanging protocol based on password to send the digital contents efficiently. The stability suggested here is based on the difficulty of the discrete algebra and Diffie-Hellman problem and also it provides a secure safety against various attacks such as a guess attack on the password.