• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.783-786
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• 2015

Hole attack, which is disturbed transmission function through change of routing information, can cause critical results for MANET as non-infrastructure network. Backhole attack, as a typical hole attack, is one malicious attack which is disabled network transmission function by assumption of transmission data through modification of routing information. It is very important to evaluate transmission performance caused by blackhole attack, because transmission performance of MANET is affective with blackhole attack. In this paper, transmission performance is analyzed with MANET under multiple blackhole attacks caused multiple blackhole nodes. Computer simulation based on NS-2 is used as analysis tool and voice traffic is considered ad application service on MANET.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.5
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• pp.27-33
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• 2011

At FDTC'05 and CISC-W'10, the authors showed that if they decrease the number of rounds of AES and Triple-DES by using the fault injections, it is possible to recover the secret key of the target algorithms, respectively. In this paper, we propose a key recovery attack on HMAC by using the main idea of these attacks. This attack is applicable to HMAC based on MD-family hash functions and can recover the secret key with the negligible computational complexity. Particularly, the attack result on HMAC-SHA-2 is the first known key recovery attack result on this algorithm.

• Journal of Internet Computing and Services
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• v.18 no.6
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• pp.35-46
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• 2017

Recently, attackers using malicious code in cyber security have been increased by attaching malicious code to a mail and inducing the user to execute it. Especially, it is dangerous because it is easy to execute by attaching a document type file. The author analysis is a research area that is being studied in NLP (Neutral Language Process) and text mining, and it studies methods of analyzing authors by analyzing text sentences, texts, and documents in a specific language. In case of attack mail, it is created by the attacker. Therefore, by analyzing the contents of the mail and the attached document file and identifying the corresponding author, it is possible to discover more distinctive features from the normal mail and improve the detection accuracy. In this pager, we proposed IADA2(Intelligent Attack mail Detection based on Authorship Analysis) model for attack mail detection. The feature vector that can classify and detect attack mail from the features used in the existing machine learning based spam detection model and the features used in the author analysis of the document and the IADA2 detection model. We have improved the detection models of attack mails by simply detecting term features and extracted features that reflect the sequence characteristics of words by applying n-grams. Result of experiment show that the proposed method improves performance according to feature combinations, feature selection techniques, and appropriate models.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.1
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• pp.15-23
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• 2017

Template attack is a powerful side-channel analysis technique which can be performed by an attacker who has a test device that is identical to target device. Template attack is consisted of building template in profiling phase and matching the target device using template that were calculated in profiling phase. One methods to improve the success rate of template attack is to better estimate template which is consisted sample mean and sample covariance matrix of gaussian distribution in template profiling. However restriction of power trace in profiling phase led to poor template estimation. In this paper, we propose new method to select noisy power trace in profiling phase. By eliminating noisy power trace in profiling phase, we can construct more advanced mean and covariance matrix which relates to better performance in template attack. We proved that the proposed method is valid through experiments.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.6
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• pp.573-584
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• 2014

In this study, the variations of cutter acting forces depending on cutting conditions were examined to obtain basic data for roadheader cutting head design. The linear cutting tests were performed in the condition of different attack angles, penetration depths, cutter spacings by using a slim conical pick for the light cutting condition. Cutter acting forces were measured by 3-directional load cell under different test conditions, and the analysis for cutting performance were carried out after calculating average values of the measured results. It is confirmed that the optimal cutting condition for the mortar specimen is the 50 degree attack angle, the cutter spacing of 12 mm, the cutting depth of 9 mm which are obtained from the analysis results. In addition, 50 degree attack angle is more effective than 45 degree attack angle to design optimal specifications of cutting head.

• Journal of the Korea Society for Simulation
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• v.21 no.4
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• pp.91-102
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• 2012

Network port scan attack is the method for finding ports opening in a local network. Most existing IDSs(intrusion detection system) record the number of packets sent to a system per unit time. If port scan count from a source IP address is higher than certain threshold, it is regarded as a port scan attack. The degree of risk about source IP address performing network port scan attack depends on attack count recorded by IDS. However, the measurement of risk based on the attack count may reduce port scan detection rates due to the increased false negative for slow port scan. This paper proposes a method of summarizing 4 types of information to differentiate network port scan attack more precisely and comprehensively. To integrate the riskiness, we present a risk index that quantifies the risk of port scan attack by using PCA. The proposed detection method using risk index shows superior performance than Snort for the detection of network port scan.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.11
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• pp.2588-2594
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• 2013

Damage is increasing by (Smishing) hacking attack Smishing you use a smart phone after entering 2013. Takeover of personal information and direct financial damage in collaboration with graphics sewing machine hacking attack has occurred. Monetary damage that leads to Internet payment service (ISP) and secure payment system in conjunction with graphics sewing machine hacking attack on a smartphone has occurred. In this paper, I will study analysis in the laboratory examples of actual infringement vinegar sewing machine hacking attack. It is a major power security measures to prevent damage to the secure payment system that a case analysis and practical principle technical nest sewing machine hacking attack, using Smishing. In this paper, I will be to research to be able to through a smart phone, to the online payment safer and more convenient.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.141-145
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• 2013

Damage is increasing by (Smishing) hacking attack Smishing you use a smart phone after entering 2013. Takeover of personal information and direct financial damage in collaboration with graphics sewing machine hacking attack has occurred. Monetary damage that leads to Internet payment service (ISP) and secure payment system in conjunction with graphics sewing machine hacking attack on a smartphone has occurred. In this paper, I will study analysis in the laboratory examples of actual infringement vinegar sewing machine hacking attack. It is a major power security measures to prevent damage to the secure payment system that a case analysis and practical principle technical nest sewing machine hacking attack, using Smishing. In this paper, I will be to research to be able to through a smart phone, to the online payment safer and more convenient.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.2
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• pp.115-123
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• 2007

In cryptographic devices like a smart-card whose computing ability and memory are limited, cryptographic algorithms should be performed efficiently. Scalar multiplication is very important operation in Elliptic Curve Cryptosystems, and so must be constructed in safety against side channel attack(SCA). But several countermeasures proposed against SCA are exposed weaknesses by new un-dreamed analysis. 'Double-and-add always scalar multiplication' algorithm adding dummy operation being known to secure against SPA is exposed weakness by Doubling Attack. But Doubling Attack cannot apply to sABS receding proposed by Hedabou, that is another countermeasure against SPA. Our paper proposes new strengthened Doubling Attacks that can break sABS receding SPA-countermeasure and a detailed method of our attacks through experimental result.

• Journal of the Korea Society of Computer and Information
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• v.17 no.2
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• pp.159-166
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• 2012

Many biometrics-based user authentication schemes using smart cards have been proposed to improve the security weaknesses in user authentication system. In 2010, Chang et al. proposed an improved biometrics-based user authentication scheme without concurrency system which can withstand forgery attack, off-line password guessing attack, replay attack, etc. In this paper, we analyze the security weaknesses of Chang et al.'s scheme and we have shown that Chang et al.'s scheme is still insecure against man-in-the-middle attack, off-line biometrics guessing attack, and does not provide mutual authentication between the user and the server. And we proposed the improved scheme to overcome these security weaknesses, even if the secret information stored in the smart card is revealed. As a result, the proposed scheme is secure for the user authentication attack, the server masquerading attack, the man-in-the-middle attack, and the off-line biometrics guessing attack, does provide the mutual authentication between the user and the remote server. And, in terms of computational complexities, the proposed scheme is more effective than Chang et al.'s scheme.