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윤정환(Junghwan Yoon),서예지(Yezee Seo),김훈규(Hoonkyu Kim),권태경(Taekyoung Kwon) 한국정보보호학회 2018 정보보호학회논문지 Vol.28 No.2
FPGA (Field Programmable Gate Array) 는 개발자가 유연하게 프로그래밍 할 수 있다는 장점으로 인해 다양한 분야에서 사용되고 있다. 하지만 외부에서 구현된 시스템이 비트스트림 형태로 FPGA에 탑재 될 경우 오작동을 일으키거나 정보를 유출시키는 등의 하드웨어 악성 기능이 포함될 가능성이 있다. 이러한 이유로 비트스트림 역공학은 필수적이며, 따라서 이와 관련된 연구들이 진행되어 왔다. 본 논문에서는 FPGA 비트스트림 역공학 연구사례 중 가장 대표적인 역공학 알고리즘을 활용한 BIL 비트스트림 역공학 도구에 대한 분석 실험을 진행하여 성능 및 한계점을 확인하였다. Field Programmable Gate Array (FPGA) is widely used in a variety of fields because of its ability to be programmed as desired. However, when an externally implemented program is loaded on FPGA in the form of a bitstream, there is a possibility that hardware Trojans which cause malfunctions or leak information may be included. For this reason, bitstream reverse engineering is essential, and therefore related research has been conducted, such as BIL. In this paper, we analyze the BIL bitstream reverse engineering tool, which is the most representative algorithm, regarding its performance and limitations.
윤정환(Junghwan Yoon),서예지(Yezee Seo),장재동(Jaedong Jang),권태경(Taekyoung Kwon) 한국정보보호학회 2018 정보보호학회논문지 Vol.28 No.5
FPGA(Field Programmable Gate Array)를 이용한 시스템 개발은 개발 시간 단축 및 비용 절감을 위해 제3자에게 아웃소싱하는 형태로 발전하고 있다. 이러한 과정에서 악의적인 기능 및 오작동을 유발하는 하드웨어 악성기능(Hardware Trojan)이 시스템에 유입될 위협 또한 증가하고 있다. 하드웨어 악성기능의 탐지를 위해 다양한 방법들이 제시되고 있으나 FPGA에 탑재되는 비트스트림을 직접 수정하는 형태의 하드웨어 악성기능은 기존에 제시된 방법으로 탐지하기 어렵다. 이러한 유형의 하드웨어 악성기능 탐지를 위해서는 비트스트림으로부터 구현된 회로를 식별 가능한 수준으로 역공학하는 과정이 필요하며, 회로를 구성하는 여러 요소 중 특히 신호의 입출력 흐름을 파악할 수 있는 연결 정보를 역공학하는 것이 중요하다. 본 논문에서는 FPGA 비트스트림으로부터 연결 정보를 복구하는 도구인 BIL을 분석하고 이를 개선하기 위한 방법을 제시한다. FPGA-based system development is being developed as a form of outsourcing that shortens the development time and reduces the cost. Through the process, the risk of letting the hardware Trojan, which causes malfunctions, seep into the system also increases. Various detection methods are proposed for the issue; however, such type of hardware Trojans is inserted by modifying a bitstream directly and therefore, it is hard to detect with the suggested methods. To detect the type of hardware Trojans, it is essential to reverse-engineer the electric circuit implemented by bitstream to a distinguishable level. Specifically, it is important to reverse-engineer the routing information of the circuit that can identify the input-output flow of the signal. In this paper, we analyze the BIL bitstream reverse-engineering tool-chain that uses the algorithm, which retrieves the routing information from FPGA bitstream, and suggest the method to improve the tool-chain.
유성환(Sunghwan Ryu),윤정환(Junghwan Yoon),윤주호(Ju-ho Yun),유승을(Seung-eul Yoo) 한국자동차공학회 2017 한국자동차공학회 부문종합 학술대회 Vol.2017 No.5
Automobile interior products are researching and developing automobile parts in three directions of high quality, environment friendly and light weight. As the living standard is improved and passengers stay in the automobile, research on environmentally friendly materials is studied in various aspects In fact. Eco-friendly materials are currently being applied to press forming other than extrusion and injection, and since the natural fiber composite material through injection molding has not been used as an automotive interior product up to now, the test piece is molded through extrusion and injection molding The matrix polymer used in this study was Polyketone (PK or POK) developed by Hyosung. The natural fiber used in this study was Kenaf (lignin removal, lignin The test specimens were prepared by extrusion molding and injection molding using fibers and Sisal (lignin-removing) fibers. The recipe was made before and after the addition of additives (antioxidants, radical formation inhibitors, UV stabilizers) After the optimized mixing ratio was selected, the test specimens were molded for each fiber content, and then the mechanical properties and chemical properties were changed through UTM, FT-IR, DSC, TGA, GCMS and FE-SEM The morphology at the interface between matrix polymer and fiber was analyzed. As a result of the study, it has been studied that the dispersion of physical properties decreases as the additives are added. As the content of fibers increases, the tensile-related properties decrease and flexural-related properties increase. As the content of fibers increases, In order to increase the dispersibility of fiber, it was confirmed by analyzing that fiber is dispersed evenly on the outer surface of specimen when glass bubble is added..