• Review of KIISC
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• v.13 no.6
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• pp.25-36
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• 2003

정보보호시스템 평가 인증 제도는 사용자들이 신뢰된 인증제품을 사용할 수 있도록 평가기준의 등급별 요구사항을 근거로 평가하여 정보보호시스템에 구현되어 있는 보안기능의 신뢰성을 보증하는데 있다. 본 연구에서는 정보보호제품의 시험 커버리지 보증을 위한 시험케이스 생성에 관한 연구로서, 평가기준에서 요구되는 시험 커버리지를 분석하고 이를 만족시키기 위한 시험케이스 생성 방법을 제시함으로써 보증성을 향상시키고자 한다.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.177-183
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• 2013

Objectives: 본 연구는 호흡보호구의 밀착도의 척도인 밀착계수 (FF)를 이용하여마스크에 마스크 커버를 씌웠을 때 호흡보호구의 밀착에 어떠한 영향을 미치는지 평가하고자 하였다. Methods: 3개 회사의 호흡보호구 (1개 1/4형, 2개 반면형)를 선정하여25의 피검자 (남자 16, 여자 9)에게 마스크 커버를 씌우지 않은 마스크와 씌운 마스크를 착용하게 하고 정량적인 밀착도 검사 (QNFT)를 실시하여 밀착계수 (FF)를 측정하였다. 동일한 조건에서 각 피검자에게 3번의 QNFT를 실시였으므로 한 마스크 당 씌운 것 75회, 씌우지 않은 것 75회, 150회를 시행하여 비교하였고 3개 마스크에 총 450회를 시행하였다. Results: 마스크 A (반면형)는 예상과는 다르게 마스크 커버가 있는 경우가 없는 경우보다 FF값이 더 높게 나왔으며 (p<0.05), 마스크 B (1/4형)와 마스크 C (반면형)은 마스크 커버가 없는 경우가 있는 경우보다 FF가 높게 나왔다. 마스크 B는 마스크 커버와 관계없이 FF가 너무 낮아 밀착에 문제가 있다고 판단되었으며 반대로 마스크 C는 마스크 커버에 영향을 받았으나 FF가 매우 높게 나와 밀착에는 큰 문제가 없다고 판단되었다. Conclusions: 본 연구 결과는 마스크에 자신의 마스크 커버를 씌울 경우 밀착에 큰 영향은 없는 것으로 나타났으나 FF만 가지고 실험했기 때문에 제한적이며 실제 작업현장에서 밀착도에 영향을 주지 않는지를 결정하기 위해서는 작업장보호계수 (WPF)를 이용한 보다 많은 연구가 필요하다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.6
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• pp.1079-1085
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• 2020

Fuzzing is used to find vulnerabilities for a library. Because library fuzzing only tests the implemented functions, in order to achieve higher code coverage, additional functions that are not implemented should be implemented. However, if a function is added without regard to the calling relationship of the functions in the library, a problem may arise that the function that has already been tested is added. We propose a novel method to improve the code coverage of library fuzzing. First, we analyze the function call graph of the library to efficiently add the functions for library fuzzing, and additionally implement a library function that has not been implemented. Then, we apply a hybrid fuzzing to explore for branches with complex constraints. As a result of our experiment, we observe that the proposed method is effective in terms of increasing code coverage on OpenSSL, mbedTLS, and Crypto++.

• Journal of Digital Convergence
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• v.13 no.11
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• pp.171-178
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• 2015

The disk cover is installed to protect brake disk and calliper and it's removed right before delivering to customers. The temperature of disk cover was measured driving test vehicles(2000cc, diesel) in this study. The highest temperature measured for the driving test(120km/h-braking(0.3G)-stop-120km/h-braking(0.5G)-stop) was $260{\sim}270^{\circ}C$ in the upper part of the disk cover and the temperature varied considerably around the disk cover. It can be inferred from this temperature distribution around the cover that the major heat transfer from hot disk to cover was through convection. In other words, the hot air generated by braking friction moved up to the upper part of the disk cover. And only the upper area of the disk cover was melted down during this driving test. The thickness of disk cover was increased to 1.0mm from 0.7mm and 1 paper of masking tape was pasted in the upper region of the disk cover. Then the cover endured the heated air formed by braking friction during the driving test.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.6
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• pp.1463-1474
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• 2018

Fuzzing is one of the software testing techniques that find security flaws by inputting invalid values or arbitrary values into the program and various methods have been suggested to increase the efficiency of such fuzzing. In this paper, focusing on the existence of field with high relevance to coverage and software crash, we propose a new method for intensively fuzzing corresponding field part while performing field based fuzzing. In this case, we use a deep learning model called Variational Autoencoder(VAE) to learn the statistical characteristic of input values measured in high coverage and it showed that the coverage of the regenerated files are uniformly higher than that of simple variation. It also showed that new crash could be found by learning the statistical characteristic of the files in which the crash occurred and applying the dropout during the regeneration. Experimental results showed that the coverage is about 10% higher than the files in the queue of the AFL fuzzing tool and in the Hwpviewer binary, we found two new crashes using two crashes that found at the initial fuzzing phase.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.106
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• pp.295-306
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• 2006

In this paper, we proposed and implemented a novel antenna cover mounted over a microstrip path antenna for ultrafast aircraft. A protective antenna cover prevents alteration in the electrical characteristics of the antenna due to environmental conditions. The permittivity of the cover materials should be practically invariable at all operating frequencies. We evaluated the characteristics of the antenna with both simulation and experiment. The experimental results show that the proposed antenna cover can be useful for ultrafast aircraft.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.3
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• pp.443-454
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• 2020

The JavaScript engine is a module that receives JavaScript code as input and processes it, among many functions that are loaded into web browsers and display web pages. Many fuzzing test studies have been conducted as vulnerabilities in JavaScript engines could threaten the system security of end-users running JavaScript through browsers. Some of them have increased fuzzing efficiency by guiding test coverage in JavaScript engines, but no coverage guided fuzzing of optimized, dynamically generated machine code was attempted. Optimized JavaScript codes are difficult to perform sufficient iterative testing through fuzzing due to the function of runtime guards to free the code in the event of exceptional control flow. To solve these problems, this paper proposes a method of performing fuzzing tests on optimized machine code by avoiding deoptimization. In addition, we propose a method to measure the coverage of runtime-guards by the dynamic binary instrumentation and to guide increment of runtime-guard coverage. In our experiment, our method has outperformed the existing method at two measures: runtime coverage and iteration by time.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.4
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• pp.587-604
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• 2021

Because the library cannot be run independently and used by many applications, it is important to detect vulnerabilities in the library. Fuzzing, which is a dynamic analysis, is used to discover vulnerabilities for the library. Although this fuzzing technique shows excellent results in terms of code coverage and unique crash counts, it is difficult to apply its effects to library fuzzing. In particular, a fuzzing executable and a seed corpus are needed that execute the library code by calling a specific function sequence and passing the input of the fuzzer to reproduce the various states of the library. Generating the fuzzing environment such as fuzzing executable and a seed corpus is challenging because it requires both understanding about the library and fuzzing knowledge. We propose a novel method to improve the ease of library fuzzing and enhance code coverage and crash detection performance by using a test framework. The systems's performance in this paper was applied to nine open-source libraries and was verified through comparison with previous studies.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.55-62
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• 2005

There are many risk factors of electrical shock caused by a minimum of protective devices, loose working environments, deterioration of installations at temporary power installations of construction sites. An insulation cover for instrument transformer(MOF) used in 22.9[kV] class power receiving system hasn't shown good performance in terms of electrical safety because of short clearance between insulation cover and each input and output wire junction part. The insulation cover is easily moved by outside environment as wind or rain because of different size between insulation cover and busing, also can be leaded to breakdown by tracking. Therefore, we have proposed the insulation cover which effectively can prevent from electrical disaster in this paper, and a utility model patent had been registered already. To decrease the electric field concentrated on specific part, we had roundly designed the shape of insulation cover and the clearance between cover and live part was adjusted to be longer than the existing thing. The proposed insulation cover was evaluated by using the electric field solution program.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.231-234
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• 2016

본 논문에서는 전송하고자 하는 원영상 대신에 전혀 다른 영상을 전송하여 원영상 정보를 보호하는 스테가노그래피(steganography) 기법을 제안한다. 전송할 영상의 자연스러움을 잃어버리지 않으면서 원영상을 복구할 수 있는 차영상 정보를 LSB(Least Significant Bit)에 담고, 픽셀간의 위치 관계를 무작위로 섞어 줌으로써, 원영상을 보호하는 기법을 제안한다. 본 논문에서는 우선 원영상과 전송할 영상 (cover image)의 차영상을 생성하고, 각 픽셀의 차이값을 큰 범위로 양자화하여 차영상의 데이터 크기를 줄인다. 그리고, 각 픽셀의 차이값을 전송할 영상의 4 픽셀에 걸쳐서 하위 2bit 에 나누어 담는다. 8bit 영상에서 하위 2 bit 를 다루기 때문에, 각 채널 밝기값의 최대 차이값은 3 으로 설정되어 자연스럽게 영상을 생성할 수 있다. 끝으로 신호의 보호를 위하여 차영상의 픽셀과 전송할 영상의 픽셀간의 대응위치를 무작위 순열로 변환하여 외부에서 쉽게 복원할 수 없도록 한다. 이러한 스테가노그래피 제안 기법을 통하여 원영상 대신에 커버 영상을 전송함으로써, 자연스러운 정보전송이 가능하며, 외부의 감시와 복원에 안전한 정보보호 기능이 강화될 수 있다. 여러 영상에 대한 실험을 통한 제안 기법에 의하면, 전송되는 커버 영상이 자연스럽기 때문에 외부에서 정보가 숨겨진 사실을 느끼지 못하며, 송수신 장치에 내장된 무작위 순열을 통하여 외부에서는 원영상 정보를 복구하는 것도 매우 어렵게 되어 있음을 확인하였다. 본 제안 기법은 군사통신이나 중요한 정보를 다루는 기관에서의 정보 전달 및 정보보호 시스템에서 사용될 수 있다.