• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.405-414
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• 2006

We present a symptom based taxonomy for network security. This taxonomy classifies attacks in the network using early symptoms of the attacks. Since we use the symptom it is relatively easy to access the information to classify the attack. Furthermore we are able to classify the unknown attack because the symptoms of unknown attacks are correlated with the one of known attacks. The taxonomy classifies the attack in two stages. In the first stage, the taxonomy identifies the attack in a single connection and then, combines the single connections into the aggregated connections to check if the attacks among single connections may create the distribute attack over the aggregated connections. Hence, it is possible to attain the high accuracy in identifying such complex attacks as DDoS, Worm and Bot We demonstrate the classification of the three major attacks in Internet using the proposed taxonomy.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.5
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• pp.3-10
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• 2004

A Wireless Lan has an importance of access control, because we can use wireless Internet via AP(Access Point). Moreover, to use wireless LAN, we will go through authentication process of EAP. DoS(Denial of Service) attack is one of the fatal attack about these AP access and authentication process. That is, if malicious attacker keeps away access of AP or consumes memory of server and calculation ability of CPU and etc. compulsorily in authentication process, legal user can't get any services. In this paper, we presents the way of protection against the each attack that is classified into access control, allocation of resource, attack on authentication protocol. The first thing, attack to access control, is improved by pre-verification and the parameter of security level. The second, attack of allocation of resource, is done by partial stateless protocol. And the weak of protocol is done by time-stamp and parameter of access limitation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.4
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• pp.673-689
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• 2022

We propose an APT attack scoring method as a part of the process for detecting and responding to APT attacks. First, unlike previous work that considered inconsistent and subjective factors determined by cyber security experts in the process of scoring cyber attacks, we identify quantifiable factors from components of MITRE ATT&CK^Ⓡ techniques and propose a method of quantifying each identified factor. Then, we propose a method of calculating the score of the unit attack technique from the quantified factors, and the score of the entire APT attack composed of one or more multiple attack techniques. We present the possibility of quantification to determine the threat level and urgency of cyber attacks by applying the proposed scoring method to the APT attack reports, which contains the hundreds of APT attack cases occurred worldwide. Using our work, it will be possible to determine whether actual cyber attacks have occurred in the process of detecting APT attacks, and respond to more urgent and important cyber attacks by estimating the priority of APT attacks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.4203-4225
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• 2014

Fuzzy identity-based cryptography introduces the threshold structure into identity-based cryptography, changes the receiver of a ciphertext from exact one to dynamic many, makes a cryptographic scheme more efficient and flexible. In this paper, we propose the first fuzzy identity-based signcryption scheme in lattice-based cryptography. Firstly, we give a fuzzy identity-based signcryption scheme that is indistinguishable against chosen plaintext attack under selective identity model. Then we apply Fujisaki-Okamoto method to obtain a fuzzy identity-based signcryption scheme that is indistinguishable against adaptive chosen ciphertext attack under selective identity model. Thirdly, we prove our scheme is existentially unforgeable against chosen message attack under selective identity model. As far as we know, our scheme is the first fuzzy identity-based signcryption scheme that is secure even in the quantum environment.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.40-51
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• 1999

This paper reviews the combat survivability and supermaneuverbility which are principal factors in current and future high performance combat aircraft design. First of all, the fighter agility evaluation factors were presented. And then, emphasis was put on technologies associated with supermaneuverbility, such as vortex lift, high angle of attack aerodynamics, thrust vectoring and control system technologies that integrate each technology. The advanced nations' supermaneuverbility R/D programs were introduced as well.

• IEMEK Journal of Embedded Systems and Applications
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• v.18 no.6
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• pp.311-317
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• 2023

This paper presents a sliding mode observer (SMO) for reconstructing cyber attacks affecting a system. The system is first re-expressed such that its design freedom is easier to manipulate. The SMO is then used to reconstruct the cyber attack affecting the system. A simulation example is used to verify the performance of the SMO under two types of cyber attacks, and its results demonstrate the effectiveness of our proposed scheme.

• The Journal of Korean Medicine
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• v.28 no.1 s.69
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• pp.25-34
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• 2007

Objectives : The present study was carried out to provide basic information necessary for the prevention and efficient treatment of stroke through a comparison between thr patients of the first attack and those of recurrence. Methods : The observation f3r the current study was made on 210 cases of stroke that were confirmed through brain CT-scan. The patients were hospitalized at one of two oriental medical hospitals in Seoul during 2006. Result : The main results were as follows. First, the male-to-female ratio of stroke patients were 1:1.26, with more primary stroke far females and more recurrent stroke for males. Second, in the age distribution, seventies was the top, and sixties, fifties, and forties were next in the order of frequency. A large city was the most frequent residential site and unemployment was the most frequent occupation to have stroke. The incidence of stroke became higher as patients had a taste for spicy and salty food. Third, the most common preceding disease was hypertension. In the relationship of diastolic blood pressure with recurrence, there was significance in the test of independence. Fourth, the most important precipitating conditions at the onset of stroke were rest and steeping. The most common precedent symptoms were verbal disturbance, numbness, and dizziness. In the stroke patients with hemiparesis, male and female patients usually showed It. hemiparesis. Fifth, as a result of brain CT-scan, cerebral hemorrhage was inclined to reduce but cerebral infarction was inclined to increase due to senility and change of lifestyle. Finally, total cholesterol findings disclosed that 22.4% were hypercholesteremia, 18.6 % were hyperlipemia in triglyceride findings, and 19.0% were glycosemia in glucose findings. Conclusions : The above results suggested avoidance of meat and salty fDod and positive control of hypertension and diabetes mellitus in order to prevent stroke.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.1272-1290
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• 2013

Privacy-preserving collaborative filtering schemes are becoming increasingly popular because they handle the information overload problem without jeopardizing privacy. However, they may be susceptible to shilling or profile injection attacks, similar to traditional recommender systems without privacy measures. Although researchers have proposed various privacy-preserving recommendation frameworks, it has not been shown that such schemes are resistant to profile injection attacks. In this study, we investigate two memory-based privacy-preserving collaborative filtering algorithms and analyze their robustness against several shilling attack strategies. We first design and apply formerly proposed shilling attack techniques to privately collected databases. We analyze their effectiveness in manipulating predicted recommendations by experimenting on real data-based benchmark data sets. We show that it is still possible to manipulate the predictions significantly on databases consisting of masked preferences even though a few of the attack strategies are not effective in a privacy-preserving environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.1094-1107
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• 2013

NTRU cryptosystem has been suggested for protecting wireless body area networks, which is secure in the sense of traditional cryptanalysis. In this paper, we fulfill the first power analysis attack on the ultra-low-power environment of wireless body area networks. Specifically, two practical differential power analyses on NTRU algorithm are proposed, which can attack the existing countermeasures of NTRU. Accordingly, we suggest three countermeasures against our attacks. Meanwhile, practical experiments show that although the attacks in this paper are efficient, our countermeasures can resist them effectively.

• Journal of the military operations research society of Korea
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• v.17 no.1
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• pp.159-176
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• 1991

The probability of target survival is the most important factor in the target assignment, Most of the studies about it have assumed the case of one target and ane weapon type. Therefore, they can not be applied to the real situation. In this paper. the quantity and type of enemy assets of the friendly force are considered simultaneously. Considered defense type is the coordinated defense with no impact point prediction. The objective function is to minimize the expected total survival value of targets which are scattered in the defense area. The rules of aircraft assignment are as follows : first, classify targets into several groups, each of those has the same desired damage level secondly. select the critical group which has the least survival value in accordance with the additional aircraft assignment, and finally. assign the same number of attack assets against each target in the critical group. In this paper, the attack assets, the escort assets, and the defense assets are considered. The model is useful to not only the simple aircraft assignment problem but also the complicated wargame models.