• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.5819-5840
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• 2018

Considering the topology of hierarchical tree structure, each cluster in WSNs is faced with various attacks launched by malicious nodes, which include network eavesdropping, channel interference and data tampering. The existing intrusion detection algorithm does not take into consideration the resource constraints of cluster heads and sensor nodes. Due to application requirements, sensor nodes in WSNs are deployed with approximately uncorrelated security weights. In our study, a novel and versatile intrusion detection system (IDS) for the optimal defense strategy is primarily introduced. Given the flexibility that wireless communication provides, it is unreasonable to expect malicious nodes will demonstrate a fixed behavior over time. Instead, malicious nodes can dynamically update the attack strategy in response to the IDS in each game stage. Thus, a multi-stage intrusion detection game (MIDG) based on Bayesian rules is proposed. In order to formulate the solution of MIDG, an in-depth analysis on the Bayesian equilibrium is performed iteratively. Depending on the MIDG theoretical analysis, the optimal behaviors of rational attackers and defenders are derived and calculated accurately. The numerical experimental results validate the effectiveness and robustness of the proposed scheme.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.41-48
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• 2019

In 2018, Cui et al proposed a three-factor remote user authentication scheme using biometrics. Cui et al claimed that their authentication scheme is vulnerable to eavesdropping attack, stolen smart card attack, and especially Dos(denial-of-service) attack. Also they claimed that it is safe to password guessing attack, impersonation attack, and anonymity attack. In this paper, however, we analyze Cui et al's authentication scheme and show that it is vulnerable to replay attack, insider attack, stolen smart card attack, and user impersonation attack, etc. In addition, we present the design flaws in Cui et al's authentication scheme as well.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.1
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• pp.103-114
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• 2008

Single Sign-On is an authentication scheme that enables a user to authenticate once and then to access to the resources of multiple software systems without re-authentication. As web services are being integrated into a single groupware, more web sites are adopting for user convenience. However, these Single Sign-On services are very dependent upon the cookies and thus, simple eavesdropping enables attackers to hiject the user's session. Even worse, the attacker who hijacked one session can move to another site through the Single Sign-On. In this paper, we show the vulnerabilities of the top ranked sites regarding this point of view and also propose a way to protect a user's session.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.125-134
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• 2008

A great number of RFID authentication protocols have been proposed for the secure RFID system. These are typically divided into three types according to primitive that they use : Hash-based, Re-encryption based, and XORing-based protocol. The well-known attacks in RFID system are eavesdropping. impersonating, location tracking, and so on. However, existing protocols could not provide security against above attacks, or it was not efficient to search for tags on database. Therefore, in this paper we present a protocol which is secure against above attacks by using hash function and makes Database search tags easily by attaining the state information of previous session through the shared values with all tags and database.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.5
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• pp.161-168
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• 2011

In 2009, Jeon et al proposed the lightweight strong authentication and strong privacy protocol, where the tag requrires only simple bitwise operations and random number generator. JK-RFID authentication protocol provides strong security: eavesdropping, replay, spoofing, Location tracking, DoS attack and forward security. Nevertheless, this paper points out the vulnerability of the forward security and improve the process of key updating. As a result, proposes an enhanced JK-RFID authentication protocol providing forward security and verify its satisfaction. In addition, a security and an efficiency of the proposed scheme analyze. Since partial adjustments of the key updating operation in JK-RFID authentication protocol, our protocol improve the forward security.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.12
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• pp.4508-4530
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• 2021

Today distributed data storage service are being widely used. However lack of proper means of security makes the user data vulnerable. In this work, we propose a Randomized Block Size (RBS) model for secure data storage in distributed environments. The model work with multifold block sizes encrypted with the Chinese Remainder Theorem-based RSA (C-RSA) technique for end-to-end security of multimedia data. The proposed RBS model has a key generation phase (KGP) for constructing asymmetric keys, and a rand generation phase (RGP) for applying optimal asymmetric encryption padding (OAEP) to the original message. The experimental results obtained with text and image files show that the post encryption file size is not much affected, and data is efficiently encrypted while storing at the distributed storage server (DSS). The parameters such as ciphertext size, encryption time, and throughput have been considered for performance evaluation, whereas statistical analysis like similarity measurement, correlation coefficient, histogram, and entropy analysis uses to check image pixels deviation. The number of pixels change rate (NPCR) and unified averaged changed intensity (UACI) were used to check the strength of the proposed encryption technique. The proposed model is robust with high resilience against eavesdropping, insider attack, and chosen-plaintext attack.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.8
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• pp.2490-2506
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• 2022

In Mobile Edge Computing (MEC), attackers can speculate and mine sensitive user information by eavesdropping wireless channel status and offloading usage pattern, leading to user privacy leakage. To solve this problem, this paper proposes a Privacy-preserving and Energy-efficient Offloading Algorithm (PEOA) based on Lyapunov optimization. In this method, a continuous Markov process offloading model with a buffer queue strategy is built first. Then the amount of privacy of offloading usage pattern in wireless channel is defined. Finally, by introducing the Lyapunov optimization, the problem of minimum average energy consumption in continuous state transition process with privacy constraints in the infinite time domain is transformed into the minimum value problem of each timeslot, which reduces the complexity of algorithms and helps obtain the optimal solution while maintaining low energy consumption. The experimental results show that, compared with other methods, PEOA can maintain the amount of privacy accumulation in the system near zero, while sustaining low average energy consumption costs. This makes it difficult for attackers to infer sensitive user information through offloading usage patterns, thus effectively protecting user privacy and safety.

• Proceedings of the Korea Information Processing Society Conference
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• 2024.05a
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• pp.175-178
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• 2024

IoT is becoming more and more popular, along with the massive availability of cheap and easy-to-use IoT devices. One protocol that is often used in IoT devices is the Message Queuing Telemetry Transport (MQTT) protocol. By default, the MQTT protocol does not activate encrypted data security features. This MQTT default feature makes the transmitted and received message data vulnerable to attacks, such as eavesdropping. Therefore, this paper will design and implement encrypted data security using the lightweight cryptography algorithm. The focus of this paper will be on securing MQTT message data at the application layer. We propose a method for encrypting specific MQTT message fields while maintaining compatibility with the protocol's functionalities. The paper then analyzes the timing performance of the MQTT-LEA implementation on the Raspberry Pi 3+. Our findings demonstrate the feasibility of using LEA at the application layer to secure MQTT message communication on resource-constrained devices.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.75-86
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• 2014

Demand for the femtocell is largely credited to the surge in a more always best connected communication conscious public. 3GPP defines new architecture and security requirement for Release 9 to deal with femtocell, Home eNode B referred as HeNB. In this paper, we analyze the HeNB security with respect to mutual authentication, access control, and secure key agreement. Our analysis pointed out that a number of security vulnerabilities have still not been addressed and solved by 3GPP technical specification. These include eavesdropping, man-in-the-middle attack, compromising subscriber access list, and masquerading as valid HeNB. To the best of our knowledge, any related research studying HeNB security was not published before. Towards this end, this paper proposes an improved authentication and key agreement mechanism for HeNB which adopts proxy-signature and proxy-signed proxy-signature. Through our elaborate analysis, we conclude that the proposed not only prevents the various security threats but also accomplishes minimum distance from use-tolerable authentication delay.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.634-645
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• 2014

VoIP (Voice over Internet Protocol) is a technology of transmitting and receiving voice and data over the Internet network. As the telecommunication industry is moving toward All-IP environment with growth of broadband Internet, the technology is becoming more important. Although the early VoIP services failed to gain popularity because of problems such as low QoS (Quality of Service) and inability to receive calls as the phone number could not be assigned, they are currently established as the alternative service to the conventional wired telephone due to low costs and active marketing by carriers. However, VoIP is vulnerable to eavesdropping and DDoS (Distributed Denial of Service) attack due to its nature of using the Internet. To counter the VoIP security threats efficiently, it is necessary to develop the criterion or the model for estimating the information security level of VoIP service providers. In this study, we developed reasonable security indicators through questionnaire study and statistical approach. To achieve this, we made use of 50 items from VoIP security checklists and verified the suitability and validity of the assessed items through Multiple Regression Analysis (MRA) using SPSS 18.0. As a result, we drew 23 indicators and calculate the weight of each indicators using Analytic Hierarchy Process (AHP). The proposed indicators in this study will provide feasible and reliable data to the individual and enterprise VoIP users as well as the reference data for VoIP service providers to establish the information security policy.