• International Journal of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.1-10
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• 2021

The purpose of the study is to contribute to the positive development of blockchain technology by providing data to examine security vulnerabilities and threats to blockchain-based services and review countermeasures. The findings of this study are as follows. Threats to the security of blockchain-based services can be classified into application security threats, smart contract security threats, and network (P2P) security threats. First, application security threats include wallet theft (e-wallet stealing), double spending (double payment attack), and cryptojacking (mining malware infection). Second, smart contract security threats are divided into reentrancy attacks, replay attacks, and balance increasing attacks. Third, network (P2P) security threats are divided into the 51% control attack, Sybil attack, balance attack, eclipse attack (spread false information attack), selfish mining (selfish mining monopoly), block withholding attack, DDoS attack (distributed service denial attack) and DNS/BGP hijacks. Through this study, it is possible to discuss the future plans of the blockchain technology-based ecosystem through understanding the functional characteristics of transparency or some privacy that can be obtained within the blockchain. It also supports effective coping with various security threats.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.6214-6242
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• 2019

Routing in mobile ad hoc networks is performed in a distributed fashion where each node acts as host and router, such that it forwards incoming packets for others without relying on a dedicated router. Nodes are mostly resource constraint and the users are usually inclined to conserve their resources and exhibit selfish behaviour by not contributing in the routing process. The trust and reputation models have been proposed to motivate selfish nodes for cooperation in the packet forwarding process. Nodes having bad trust or reputation are detected and secluded from the network, eventually. However, due to the lack of proper identity management and use of non-persistent identities in ad hoc networks, malicious nodes can pose various threats to these methods. For example, a malicious node can discard the bad reputed identity and enter into the system with another identity afresh, called whitewashing. Similarly, a malicious node may create more than one identity, called Sybil attack, for self-promotion, defame other nodes, and broadcast fake recommendations in the network. These identity-based attacks disrupt the overall detection of the reputation systems. In this paper, we propose a reputation-based scheme that detects selfish nodes and deters identity attacks. We address the issue in such a way that, for normal selfish nodes, it will become no longer advantageous to carry out a whitewash. Sybil attackers are also discouraged (i.e., on a single battery, they may create fewer identities). We design and analyse our rationale via game theory and evaluate our proposed reputation system using NS-2 simulator. The results obtained from the simulation demonstrate that our proposed technique considerably diminishes the throughput and utility of selfish nodes with a single identity and selfish nodes with multiple identities when compared to the benchmark scheme.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.6
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• pp.1165-1170
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• 2022

In WSNs, a clustering algorithm groups sensor nodes on a unit called cluster and periodically selects a cluster head (CH) that acts as a communication relay on behalf of nodes in each cluster for the purpose of energy conservation and relay efficiency. Meanwhile, attack techniques also have emerged to intervene in the CH election process through compromised nodes (inside attackers) and have a fatal impact on network operation. However, existing countermeasures such as encryption key-based methods against outside attackers have a limitation to defend against such inside attackers. Therefore, we propose a statistical detection method that detects abnormal CH election behaviors occurs in a WSN cluster. We design two attack methods (Selfish and Greedy attacks) and our proposed defense method in WSNs with two clustering algorithms and conduct experiments to validate our proposed defense method works well against those attacks.

• Convergence Security Journal
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• v.19 no.2
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• pp.11-19
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• 2019

The blockchain is a technique for managing transaction data in distributed computing manner without the involvement of central trust authority. The blockchain has been used in various area such as manufacturing, culture, and public as well as finance because of its advantage of the security, efficiency and applicability. In the blockchain, it was considered safe against 51% attack because the adversary could not have more than 50% hash power. However, there have been cases caused by large-scale computing attacks such as 51% and selfish mining attack, and the frequency of these attacks is increasing. In addition, since the development of quantum computers can hold exponentially more information than their classical computer, it faces a new type of threat using quantum algorithms. In this paper, we perform the security analysis of blockchain attacks composing the large computing capabilities including quantum computing attacks. Finally, we suggest the technologies and future direction of the blockchain development in order to be safe against large-scale computing attacks.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.69-71
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• 2022

비트코인은 현재 가장 많이 사용하는 전자 화폐 거래 시스템으로, Proof-of-Work를 합의 알고리즘으로 사용한다. 이때 비트코인에 대한 다양한 공격기법들이 연구되었으며 대표적으로 Selfish Mining과 블록 보류 공격이 존재한다. 본 논문에서는 블록 보류 공격에 대한 방지 기법의 동향에 대해서 조사하였으며, 대표적으로 딥러닝, 평판 기반 블록체인, 게임 전략을 통한 방지 기법이 존재하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.9
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• pp.3639-3662
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• 2020

The network capability to accomplish its functions in a timely fashion under failures and attacks is known as survivability. Ad hoc routing protocols have been studied and extended to various domains, such as Intelligent Transport Systems (ITSs), Unmanned Aerial Vehicles (UAVs), underwater acoustic networks, and Internet of Things (IoT) focusing on different aspects, such as security, QoS, energy. The existing solutions proposed in this domain incur substantial overhead and eventually become burden on the network, especially when there are fewer attacks or no attack at all. There is a need that the effectiveness of these routing protocols be analyzed in the presence of Denial of Service (DoS) attacks without any intrusion detection or prevention system. This will enable us to establish and identify the inherently stable routing protocols that are capable to survive longer in the presence of these attacks. This work presents a DoS attack case study to perform theoretical analysis of survivability on node and network level in the presence of DoS attacks. We evaluate the performance of reactive and proactive routing protocols and analyse their survivability. For experimentation, we use NS-2 simulator without detection or prevention capabilities. Results show that proactive protocols perform better in terms of throughput, overhead and packet drop.

• Journal of Popular Narrative
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• v.25 no.3
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• pp.181-209
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• 2019

The purpose of this article is to compare zombie narratives in relation to the Other. In previous research, the view of zombies as post-capitalist soulless consumers or workers has been frequently expressed. But in this article, I wanted to look at zombies as the main cause of the collapse of the world and a new future. First, zombies do not only mean the representation of the consumer in the late capitalist era. Rather, it is an awakening subject desiring the outside of the system. As you can see from the Uncanny's point of view, zombies are something that we should oppress as freaks and monsters that threatened the Other. To be a zombie in this way is to meet one's other self, the "Fundamentals of Humanity," and it is the moment when everything becomes the subject ex nihilo, the new beginning. Second, the concept of infection shows a new ethic. Zombie cannibalism is different from the selfish love of a vampire who sucks a worker's blood. Zombie cannibalism is an infection, which is a model of Christian love for one's neighbor. It is a moment of awakening and the beginning of solidarity. It is on the waiting for the solidarity that the zombie hangs in such a way, and the attack on the human being is an active illusion. Third, the situation of the end of a zombie narrative is another event for newness. The anger of a zombie serves not just to show monsters, but acts as a catalyst that accelerates the world's catastrophes. The anger of zombies is the messianic violence that stops the false world, and presents a new way. The emergence of zombies and the popular response to them embody a desire for the possibility of a new subject and world.