• Title/Summary/Keyword: 버퍼 APIs

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A Real-Time Multiple Circular Buffer Model for Streaming MPEG-4 Media (MPEG-4 미디어 스트리밍에 적합한 실시간형 다중원형버퍼 모델)

  • 신용경;김상욱
    • Journal of KIISE:Computing Practices and Letters
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    • v.9 no.1
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    • pp.13-24
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    • 2003
  • MPEG-4 is a standard for multimedia applications and provides a set of technologies to satisfy the needs of authors, service providers and end users alike. In this paper, we suggest a Real-time Multiple Circular Buffer (M4RM Buffer) model, which is suitable for streaming these MPEG-4 contents efficiently. M4RM buffer generates each structure of the buffer, which matches well with each object composing an MPEG-4 content, according to the transferred information, and manipulates multiple read/write operations only by its reference. It divides the decoder buffer and the composition buffer, which are described in the standard, by the unit of frame allocated to minimize the range of access. This buffer unit of a frame is allocated according to the object description. Also, it processes the objects synchronization within the buffer and provides APIs for an efficient buffer management to process the real-time user events. Based on the performance evaluation, we show that M4RM buffer model decreases the waiting time in a buffer frame, and so allows the real-time streaming of an MPEG-4 content using the smaller size of the memory block than IM1-2D and Window Media Player.

An Empirical Study of Security for API in Windows Systems (윈도우즈에서 제공되는 기본 API에 대한 안전성 고찰)

  • Choi, Young-Han;Kim, Hyoung-Chun;Oh, Hyung-Geun;Lee, Do-Hoon
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.2
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    • pp.75-82
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    • 2009
  • In this paper, we test for security targeting on APIs of Windows as that is used by many people worldwide. In order to test APIs in DLL fils of Windows OS, we propose Automated Windows API Fuzz Testing(AWAFT) that can execute fuzz testing automatically and implemented the practical tool for AWAFT. AWAFT focuses on buffer overflows and parsing errors of function parameters. Using the tool, we found 177 errors in the system folder of Windows XP SP2. Therefore, AWAFT is useful for security testing of Windows APIs. AWAFT can be applied to libraries of third party software in Windows OS for the security.

Buffer Overflow Malicious Code Detection by Tracing Executable Area of Memory (메모리 실행영력 추적을 사용한 버퍼오버플로 악성코드 탐지기법)

  • Choi, Sung-Woon;Cho, Jae-Ik;Moon, Jong-Sub
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.5
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    • pp.189-194
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    • 2009
  • Most of anti-virus programs detect and compare the signature of the malicious code to detect buffer overflow malicious code. Therefore most of anti-virus programs can't detect new or unknown malicious code. This paper introduces a new way to detect malicious code traces memory executable of essentials APIs by malicious code. To prove the usefulness of the technology, 7 sample codes were chosen for compared with other methods of 8 anti-virus programs. Through the simulation, It turns out that other anti-virus programs could detect only a limited portion of the code, because they were implemented just for detecting not heap areas but stack areas. But in other hand, I was able to confirm that the proposed technology is capable to detect the malicious code.