• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.11a
• /
• pp.322-325
• /
• 2010

본 논문은 다른 프로세서간의 어셈블리 코드를 자동으로 변환하는 방법에 대해 소개한다. 어셈블리 언어는 기계어를 사람이 알아보기 쉽도록 만든 저급 언어로서 레지스터 접근과 같은 하드웨어 수준의 작업이 가능한 반면, 컴퓨터 아키텍처에 따라 어셈블리도 다르다. 이에 따라 새로운 프로세서에서 어셈블리 코드가 포함된 프로그램을 동작시키기 위해서는 어셈블리 코드 부분을 새로 작성하여야 한다. 어셈블리를 작성하는 것은 많은 시간이 필요하고 버그가 발생할 확률이 높다. 본 논문에서는 새로 작성할 어셈블리 코드를 동일한 동작을 하는 다른 프로세서의 어셈블리 코드를 통해 생성해내는 방법을 소개한다.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.29 no.2
• /
• pp.275-285
• /
• 2019

Web-assemblies are a new binary standard designed to improve the performance of Web browser JavaScript. Web-assemblies are becoming a new web standard that can run at near native speed with efficient execution, concise representation, and code written in multiple languages. However, current Web-assembly vulnerability verification is limited to the Web assembly interpreter language, and vulnerability verification of Web-assembly binary itself is insufficient. Therefore, it is necessary to verify the safety of the web assembly itself. In this paper, we analyze how to operate the web assembly and verify the safety of the current web-assembly. In addition, we examine vulnerability of existing web -assembly and analyze limitations according to existing safety verification method. Finally, we introduce web-assembly API based fuzzing method to overcome limitation of web-assembly safety verification method. This verifies the effectiveness of the proposed Fuzzing by detecting crashes that could not be detected by existing safety verification tools.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.31 no.4
• /
• pp.753-762
• /
• 2021

WebAssembly(WASM) is a low-level instruction format that can be run in a web environment. Since WASM has a excellent performance, various web applications use webassembly. However, according to our security analysis WASM has a security pitfall related to control flow integrity (CFI) for indirect calls. To address the problem in this paper we propose a new code instrumentation scheme to protect indirect calls, named WACFI. Specifically WACFI enhances a CFI technique for indirect call in WASM based on source code anlysis and binary instrumentation. To test the feasibility of WACFI, we applied WACFI to a sound-encoding application. According to our experimental results WACFI only adds 2.75% overhead on the execution time while protecting indirect calls safely.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06c
• /
• pp.25-27
• /
• 2012

디노버 어셈블리는 레퍼런스 시퀀스 없이 리드의 염기 서열 정보를 이용하여 원래의 전체 시퀀스(original sequence)로 추정되는 시퀀스로 리드들을 재구성하는 방식이다. 최근의 NGS(Next Generation Sequencing) 기술은 대용량 리드를 훨씬 쉽게 저비용으로 생성할 수 있다는 장점이 있어, 이를 이용한 많은 연구가 이루어지고 있다. 그러나 NGS 리드 데이터를 이용한 디노버 어셈블리에 관한 연구는 국내외적으로 매우 미흡한 실정이다. 그 이유는 NGS 리드 데이터를 이용하여 디노버 어셈블리를 수행하는 경우 대용량 데이터, 복잡한 데이터 구조 및 처리 과정 등으로 인하여 매우 많은 시간과 공간이 소요될 뿐만 아니라 아직까지 다양한 분석 툴과 노하우 등이 충분히 개발되어 있지 않기 때문이다. 본 연구에서는 NGS 리드 데이터를 이용한 어셈블리의 실효성과 정확성을 검증한다. 또한 디노버 어셈블리의 처리 시간 및 공간 오버헤드를 해결하기 위하여 유사 종과의 리드 정렬을 활용하는 방안을 제안한다.

• Journal of the Society of Naval Architects of Korea
• /
• v.38 no.2
• /
• pp.79-86
• /
• 2001

This study shows an attempt to generate an assembly sequence and its model for a ship block assembly using the graph theory and graph algorithms. To generate the ship block assembly, we propose four levels of the ship block assembly model such as "geometry mode1", "relational model", "sequential mode1", and "hierarchical model". To obtain the relational model, we used surface and surface intersection algorithm. The sequential model that represents a possible assembly sequence is made by using several graph algorithms from the relational model. The hierarchical model will be constructed from the sequential model in order to represent the block assembly tree and so forth. The purpose of the hierarchical model is to define an assembly tree and to generate the Bill Of Material(BOM). Lastly, the validity of the method proposed in this study is examined with application to ship block assembly models of a single type and double type according to four models mentioned above.

• KIISE Transactions on Computing Practices
• /
• v.20 no.9
• /
• pp.513-518
• /
• 2014

It has become possible for small scale laboratories to interpret large scale genomic DNA, thanks to the reduction of the sequencing cost by the development of next generation sequencing (NGS). De novo assembly is a method which creates a putative original sequence by reconstructing reads without using a reference sequence. There have been various study results on de novo assembly, however, it is still difficult to get the desired results even by using the same assembly procedures and the analysis tools which were suggested in the studies reported. This is mainly because there are no specific guidelines for the assembly procedures or know-hows for the use of such analysis tools. In this study, to resolve these problems, we introduce steps to finding whole genome of an unknown DNA via NGS technology and de novo assembly, while providing the pros and cons of the various analysis tools used in each step. We used 350Mbp of Toxocara canis DNA as an application case for the detailed explanations of each stated step. We also extend our works for prediction of protein-coding genes and their functions from the draft genome sequence by comparing its homology with reference sequences of other nematodes.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2001.11a
• /
• pp.102-110
• /
• 2001

대부분의 해킹 공격은 공격 대상 프로그램의 소스코드 보안취약점에 의해서 발생하지만 프로그램 개발시에 소스코드 보안성에 대해서는 고려되지 않았다. 이러한 문제점으로 인하여 해킹 공격의 근본적인 원인을 해결할 수 없었다. 본 논문에서는 취약점의 원인이 되는 코드를 컴파일시 생성된 어셈블리 코드 수준에서 탐지하는 방법을 제시하고자 한다. 취약한 코드를 컴파일러 수준에서 점검하는 것보다 어셈블리 코드 수준에서 점검하는 것은 어느 정도의 메모리 영역까지 점검할 수 있어 더 정확하다.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.33 no.2
• /
• pp.337-344
• /
• 2023

Modern OSs, including Linux, show high scalability by adopting a monolithic kernel design, but have weak security because they share all memory space. This study presents a kernel module that are isolated inside the kernel using WebAssembly. WebAssembly provides a high-performance virtual machine by defining a low-level instruction set while guaranteeing memory safety. In this paper, the WebAssembly execution environment is implemented inside the kernel, allowing developers to control the operation of kernel modules and achieving higher security.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.10a
• /
• pp.264-264
• /
• 2003

• International Journal of Highway Engineering
• /
• v.9 no.2 s.32
• /
• pp.101-114
• /
• 2007

Dowel bars in the jointed concrete pavement are used to both provide load transfer across pavements joints and prevent the joint faulting leading to longer service life. On the contrary, the misplacement of dowel bar can provide negative results including the joint freezing(locking) that may cause the joint spatting and unexpected mid-slab cracking. The dowel bar can be placed using the assembly or dowel bar inserter (DBI) during the concrete pavement construction. In the domestic practice of the concrete pavement construction, the dowel bar is placed using the assembly method. This study primarily focuses on the comparison of these two dowel placement methods using the field data from the KHC test road in which both dowel placement methods have been applied to a certain length of the concrete pavement. The field data regarding the alignment of the dowel bars placed by both methods was collected using MIT-SCAN2, a nondestructive measuring equipment, and processed to compute Joint Score and Running Ave. Joint Score which are used as indicators of the dowel bar performance. The comparison of the methods for the dowel bar placement using these indicators shows that the DBI method provided much better alignment of the dowel bars reducing the risk of joint freezing than the assembly method. In order to improve the quality of the dowel bar placement using the assembly method, the current weak points of the assembly method including the fabrication, storage, and installation of dowel bar assembly were investigated and the solution was suggested. The improved dowel bar sets based on the suggested solution have been applied to an actual practice of the concrete pavement construction. The field data shows that the improved assembly method suggested in this study can highly reduce the risk of joint freezing.