• Journal of information and communication convergence engineering
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• v.15 no.1
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• pp.14-20
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• 2017

In this paper, we discuss physical layer security techniques in downlink networks, including eavesdroppers. The main objective of using physical layer security is delivering a perfectly secure message from a transmitter to an intended receiver in the presence of passive or active eavesdroppers who are trying to wiretap the information or disturb the network stability. In downlink networks, based on the random feature of channels to terminals, opportunistic user scheduling can be exploited as an additional tool for enhancing physical layer security. We introduce user scheduling strategies and discuss the corresponding performances according to different levels of channel state information (CSI) at the base station (BS). We show that the availability of CSI of eavesdroppers significantly affects not only the beamforming strategy but also the user scheduling. Eventually, we provide intuitive information on the effect of CSI on the secrecy performance by considering three scenarios: perfect, imperfect, and absence of eavesdropper's CSI at the BS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1249-1272
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• 2016

In this paper, we propose a symmetric key establishment scheme for wireless sensor networks which tries to minimize the resource usage while satisfying the security requirements. This is accomplished by taking advantage of the communication pattern of wireless sensor networks and adopting heterogeneous wireless sensor networks. By considering the unique communication pattern of wireless sensor networks due to the nature of information gathering from the physical world, the number of keys to be established is minimized and, consequently, the overhead spent for establishing keys decreases. With heterogeneous wireless sensor networks, we can build a hybrid scheme where a small number of powerful nodes do more works than a large number of resource-constrained nodes to provide enhanced security service such as broadcast authentication and reduce the burden of resource-limited nodes. In addition, an on-demand key establishment scheme is introduced to support extra communications and optimize the resource usage. Our performance analysis shows that the proposed scheme is very efficient and highly scalable in terms of storage, communication and computation overhead. Furthermore, our proposed scheme not only satisfies the security requirements but also provides resilience to several attacks.

• Journal of Information Processing Systems
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• v.5 no.3
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• pp.117-130
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• 2009

By providing ubiquitous Internet connectivity, wireless networks offer more convenient ways for users to surf the Internet. However, wireless networks encounter more technological challenges than wired networks, such as bandwidth, security problems, and handoff latency. Thus, this paper proposes new technologies to solve these problems. First, a Security Access Gateway (SAG) is proposed to solve the security issue. Originally, mobile terminals were unable to process high security calculations because of their low calculating power. SAG not only offers high calculating power to encrypt the encryption demand of SAG's domain, but also helps mobile terminals to establish a multiple safety tunnel to maintain a secure domain. Second, Robust Header Compression (RoHC) technology is adopted to increase the utilization of bandwidth. Instead of Access Point (AP), Access Gateway (AG) is used to deal with the packet header compression and de-compression from the wireless end. AG's high calculating power is able to reduce the load on AP. In the original architecture, AP has to deal with a large number of demands by header compression/de-compression from mobile terminals. Eventually, wireless networks must offer users "Mobility" and "Roaming". For wireless networks to achieve "Mobility" and "Roaming," we can use Mobile IPv6 (MIPv6) technology. Nevertheless, such technology might cause latency. Furthermore, how the security tunnel and header compression established before the handoff can be used by mobile terminals handoff will be another great challenge. Thus, this paper proposes to solve the problem by using Early Binding Updates (EBU) and Security Access Gateway (SAG) to offer a complete mechanism with low latency, low handoff mechanism calculation, and high security.

• Convergence Security Journal
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• v.7 no.4
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• pp.115-121
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• 2007

Due on failures of communication nodes for the wireless and wired networks, mobile agents may be blocked even if there is available service in the networks. To solve it, we propose migration policy with reordering of the paths to guarantee the migration of mobile agents and the paper will provide the extension with the autonomous migration of mobile agents.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1348-1353
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• 2013

The increasing demand of users for various wireless communication services has lead to the development with uniting co-existence of different and wireless networks. Each one of the these wireless networks has its own unique characteristics, as compared to other networks. An integrated security mechanism is one of the key issue in the open wireless network. To realize overall security mechanism in open wireless architecture, we should provide practical workable framework for the realization of the integrated security challenges. In this paper, we analysed integrated security platform and considerations based on the security concept.

• International Journal of Computer Science & Network Security
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• v.21 no.11
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• pp.105-110
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• 2021

Contact between Vehicle-to-vehicle and vehicle-to-infrastructural is becoming increasingly popular in recent years due to their crucial role in the field of intelligent transportation. Vehicular Ad-hoc networks (VANETs) security and privacy are of the highest value since a transparent wireless communication tool allows an intruder to intercept, tamper, reply and erase messages in plain text. The security of a VANET based intelligent transport system may therefore be compromised. There is a strong likelihood. Securing and maintaining message exchange in VANETs is currently the focal point of several security testing teams, as it is reflected in the number of authentication schemes. However, these systems have not fulfilled all aspects of security and privacy criteria. This study is an attempt to provide a detailed history of VANETs and their components; different kinds of attacks and all protection and privacy criteria for VANETs. This paper contributed to the existing literature by systematically analyzes and compares existing authentication and confidentiality systems based on all security needs, the cost of information and communication as well as the level of resistance to different types of attacks. This paper may be used as a guide and reference for any new VANET protection and privacy technologies in the design and development.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.744-747
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• 2008

Sensor networks will play an important role in the next generation pervasive computing. But its characteristic of wireless communication brings a peat challenge to the security measures used in the communication protocols. These measures are different from conventional security methods. In this paper, we proposed a security architecture for self-organizing mobile wireless sensor networks. It can prevent most of attacks based on intrusion detection.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.1
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• pp.52-83
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• 2009

In this technical report, we have examined the basic building blocks of mobile ad-hoc networks. The paper discusses various security requirements of ad-hoc networks, attacks in ad-hoc networks, Security Implementation and Routing Protocols. The primary purpose of the paper is to address the Optimized Link State Routing (OLSR) protocol in detail, along with the various possible attacks. Finally, algorithms for securing OLSR are proposed, via the addition of digital signatures, as well as more advanced techniques such as cross checking of advertised routing control data with the node's geographical position. The main aim of this research work is the addition of security features to the existing OLSR protocol. In order to effectively design a secure routing protocol, we present a detailed literature survey of existing protocols, along with the various attacks. Based on the information gathered from the literature survey, a secure routing protocol for OLSR is proposed. The proposed secure routing protocol involves the addition of a digital signature as well as more advanced techniques such as the reuse of previous topology information to validate the actual link state. Thus, the main objective of this work is to provide secure routing and secure data transmission.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.2
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• pp.13-18
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• 2011

Security supports are a significant factor in mobile ad hoc networks. Especially in dynamic topologies, considering cluster, key management is essential to provide a secure system. Recently, Li-Liu proposed iD-based multiple key management scheme for cluster-based ad hoc networks. However, we found the security weakness of their scheme. In this paper, we analyze the security of Li-Liu's scheme and show that master secret key and fragment of the master secret key can be revealed to compromised CHs and nodes. Furthermore, we propose a solution to improve the scheme against disclosure of the share key and the master secret key even though system parameters are opened to compromised nodes and modify the Li-Liu's scheme fitted for a scalable networks. The improved IMKM scheme could be usefully applied in dynamic cluster-based MANETs such as the military battlefields, mobile marketplace and VANETs.

• Convergence Security Journal
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• v.21 no.1
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• pp.55-62
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• 2021

Recently, the use of sensor devices is gradually increasing. As various sensor device emerge and the related technologies advance, there has been a dramatic increase in the interest in heterogeneous wireless sensor networks (WSNs). While sensor device provide us many valuable benefits, automatically and remotely supported services offered and accessed remotely through WSNs also exposes us to many different types of security threats. Most security threats were just related to information leakage and the loss of authentication among the involved parties: users, sensors and gateways. An user authentication protocol for wireless sensor networks is designed to restrict access to the sensor data only to user. In 2019, Chen et al. proposed an efficient user authentication protocol. However, Ryu et al. show that it's scheme still unstable and inefficient. It cannot resist offline password guessing attack and session key attack. In this paper, we propose an improved protocol to overcome these security weaknesses by storing secret data in device. In addition, security properties like session-key security, perfect forward secrecy, known-key security and resistance against offline password attacks are implied by our protocol.