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You I.,Korean Bible University | Yim K.,Soonchunhyang University
Proceedings - 2010 International Conference on Broadband, Wireless Computing Communication and Applications, BWCCA 2010 | Year: 2010

As the obfuscation is widely used by malware writers to evade antivirus scanners, so it becomes important to analyze how this technique is applied to malwares. This paper explores the malware obfuscation techniques while reviewing the encrypted, oligomorphic, polymorphic and metamorphic malwares which are able to avoid detection. Moreover, we discuss the future trends on the malware obfuscation techniques. © 2010 IEEE.


Chen Y.-S.,National Taipei University | Cho C.-H.,National Taipei University | You I.,Korean Bible University | Chao H.-C.,National Ilan University | Chao H.-C.,National Dong Hwa University
Simulation Modelling Practice and Theory | Year: 2011

Cognitive radio technique is the next step toward efficient wireless bandwidth utilization. While some of the spectrum bands (unlicensed band) have been increasingly used, most of the other spectrum resources (licensed band) are underutilized. This drives the challenges of open spectrum and dynamic spectrum access concepts, which allows unlicensed users (or called secondary users, SUs) equipped with cognitive radios to opportunistically access the spectrum not used by licensed users (or called primary users, PUs). Most existing results mainly focus on designing the lower-layer cognitive radio problems. In the literature, this is the first result to investigate the higher-layer solution for cognitive radio networks. In this paper, we present a cross-layer protocol of spectrum mobility (layer-2) and handover (layer-3) in cognitive LTE networks. With the consideration of the Poisson distribution model of spectrum resources, a cross-layer handoff protocol with the minimum expected transmission time is developed in cognitive LTE networks. Performance analysis of the proposed handoff protocol is investigated. Finally, simulation results illustrates the proposed handoff protocol significantly reduces the expected transmission time and the spectrum mobility ratio. © 2010 Elsevier B.V. All rights reserved.


Doh I.,Ewha Womans University | Lim J.,Korean Bible University | Chae K.,Ewha Womans University
Mobile Information Systems | Year: 2011

In medical sensor networks, sensor nodes on a body of the patient sense the vital data and deliver them to the server system through mobile devices or gateways in the middle. However, when these linking devices do not function because of the battery outage or the system fault, the server system could not get patients' data during that period, and this situation could lead to serious problems. In this paper, to cope with this problem, we propose a distributed authentication mechanism in which substituted devices could be authenticated to deliver patients' data to the server system in the unusual situation. © 2011-IOS Press and the authors. All rights reserved.


Lee J.-H.,Telecom Bretagne | Bonnin J.-M.,Telecom Bretagne | You I.,Korean Bible University | Chung T.-M.,Sungkyunkwan University
IEEE Transactions on Industrial Electronics | Year: 2013

IPv6 mobility management is one of the most challenging research topics for enabling mobility service in the forthcoming mobile wireless ecosystems. The Internet Engineering Task Force has been working for developing efficient IPv6 mobility management protocols. As a result, Mobile IPv6 and its extensions such as Fast Mobile IPv6 and Hierarchical Mobile IPv6 have been developed as host-based mobility management protocols. While the host-based mobility management protocols were being enhanced, the network-based mobility management protocols such as Proxy Mobile IPv6 (PMIPv6) and Fast Proxy Mobile IPv6 (FPMIPv6) have been standardized. In this paper, we analyze and compare existing IPv6 mobility management protocols including the recently standardized PMIPv6 and FPMIPv6. We identify each IPv6 mobility management protocol's characteristics and performance indicators by examining handover operations. Then, we analyze the performance of the IPv6 mobility management protocols in terms of handover latency, handover blocking probability, and packet loss. Through the conducted numerical results, we summarize considerations for handover performance. © 2012 IEEE.


Yan Z.,Beijing Jiaotong University | Zhou H.,Beijing Jiaotong University | You I.,Korean Bible University
Journal of Wireless Mobile Networks, Ubiquitous Computing, and Dependable Applications | Year: 2010

In this paper, we propose a Network-based NEtwork MObility supporting scheme (N-NEMO) in Proxy Mobile IPv6 (PMIPv6) network, which is an issue still up in the air for the basic PMIPv6 protocol. The N-NEMO, like PMIPv6, bases mobility support on network functionality, thus enabling conventional (i.e., not mobility-enabled) IP devices to change their point of attachment without disrupting ongoing communications. As a result, N-NEMO enables off-the-shelf IP devices to roam within the fixed infrastructure, attach to a mobile network and move with it, and also roam between fixed and mobile points of attachment while using the same IP address. Besides, a tunnel splitting scheme is used in N-NEMO to differentiate the inter-Mobility Access Gateway (MAG) mobility and intra-MAG mobility. The analyzing results show that N-NEMO reduces the signaling cost significantly and enhances the efficiency and scalability of network mobility in the PMIPv6 context.


Han J.,Korean Bible University
International Journal of Electrical and Computer Engineering | Year: 2015

In certain applications, fingerprint authentication systems require templates to be stored in databases. The possible leakage of these fingerprint templates can lead to serious security and privacy threats. Therefore, with the frequent use of fingerprint authentication on mobile devices, it has become increasingly important to keep fingerprint data safe. Due to rapid developments in optical equipment, biometric systems are now able to gain the same biometric images repeatedly, so strong features can be selected with precision. Strong features refer to high-quality features which can be easily distinguished from other features in biometric raw images. In this paper, we introduce an algorithm that identifies these strong features with certain probability from a given fingerprint image. Once values are extracted from these features, they are used as the authentication data. Using the geometric information of these strong features, a cancelable fingerprint template can be produced, and the process of extracting values and geometric information is further explained. Because this is a light-weight authentication scheme, this template has practical usage for low performance mobile devices. Finally, we demonstrate that our proposed schemes are secure and that the user's biometric raw data of the fingerprint are safe, even when the mobile device is lost or stolen. Copyright © 2015 Institute of Advanced Engineering and Science. All rights reserved.


Lee Y.,Korea National University of Education | Choi J.,Korean Bible University
Internet and Higher Education | Year: 2013

This study examined the effects of internal academic locus of control (ALOC), learning strategies, flow experience, and student satisfaction on student retention in online learning courses. A total number of 282 adult students at the Korea National Open University participated in the study by completing an online survey adopted from previous studies to measure the levels of five variables: internal ALOC, use of learning strategies, flow experience, satisfaction, and retention. We employed a structural equation model (SEM) to test our conceptual model using AMOS 18.0. The research findings indicate that there were significant direct effects between internal ALOC and retention, between satisfaction and retention, between internal ALOC and satisfaction, between flow and satisfaction, and between learning strategies and flow. Moreover, we noted the significant mediating effects of student satisfaction and students' experience of flow on their retention in the model. © 2012 Elsevier Inc. All rights reserved.


Qian Z.,Nanjing University | Chen C.,Nanjing University | You I.,Korean Bible University | Lu S.,Nanjing University
Computers and Mathematics with Applications | Year: 2012

Current research on UHF RFID system security mainly focus on protecting communication safety and information privacy between a pair of specific tags and its corresponding interrogation reader. However, instead of stealing detailed private information of tags, adversaries may just want to estimate the cardinality of tags, which is named counting attack. Unfortunately, most existing protocols are vulnerable to counting attack. To defend against this attack, in this paper we propose ACSP, a novel Anti-Counting Security Protocol. ACSP employs session identifier and provides a corresponding authentication metric to verify the commands sent by the reader. To handle counting attack, ACSP periodically updates the session identifier, and securely identifies tags with encryption. We evaluate the performance of ACSP through theoretical analysis and qualitative comparison. Results show that ACSP can efficiently withstand counting attack as well as defending against regular security threats as existing protocols. © 2011 Elsevier Ltd. All rights reserved.


Li X.,Nanjing University | Qian Z.,Nanjing University | You I.,Korean Bible University | Lu S.,Nanjing University
International Journal of Information Management | Year: 2014

The past few years have witnessed an explosive popularity of mobile services, especially in the form of smart phone applications. To cope with the limited batteries and computational capacities of mobile devices, prior studies suggest to deploy service instances in clouds for accomplishing most of the computation-intensive tasks. Service composition, which compensates for the simplicity of single service, is an effective way to utilize the plentiful services on the clouds all over the world. In this paper, we focus on the problem of service instance selection with service instance replica limitation constraint. The objective is to select the optimal set of service instances, which composes the integrated service and brings out the optimal QoS (quality of service), in terms of service response time. To characterize the problem, we establish a new QoS model, which considers the comprehensive quality over all users, not just for any single user or service instance. We prove that the problem is NP-hard, since many functionally equivalent service instances spread all over the distributed clouds. To address the problem, we classify the problem into three cases, including two special cases and the general case. We present two effective heuristic algorithms to determine the service instances selection for the two special cases, which are still NP-hard. The two special cases provide empirical bounds for the general case. We propose an algorithm that simulates a vote procedure for the users in the general case. The selected service instances, which come from the vote procedure, can satisfy a majority of users. We conduct extensive simulations for all of the algorithms. The simulation results show that our algorithms work efficiently on service response time reduction. © 2013 Elsevier Ltd.


You I.,Korean Bible University | Hori Y.,Kyushu University | Sakurai K.,Kyushu University
Journal of Wireless Mobile Networks, Ubiquitous Computing, and Dependable Applications | Year: 2011

In order to protect Mobile Internet Protocol Version 6 (MIPv6), considerable researches have been made, consequently followed by various security protocols, which are based on public key cryptography. Especially, depending on a proper address based public key method, these protocols use each node's address as a public key certificate to authenticate its public key because no global public key infrastructure is available in MIPv6 environments. In addition, they execute an appropriate address test to check if a node exists at its claimed address. With such security features, the protocols prevent critical attacks including redirect, man-in-the middle, and denial of service ones. On the other hand, it is clearly of paramount importance to formally evaluate the MIPv6 security protocols to design them without flaws. Unfortunately, there is lack of the formal verification method to precisely reason about their correctness while considering their unique security properties to our best knowledge. In this paper, we propose an extended SVO logic for the thorough verification of the MIPv6 security protocols. Then, we show its effectiveness by applying the proposed logic to four security protocols.

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