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Baby-Step 2k-ary Adult-Step Algorithm for Symmetric-Key Decryption (대칭키 해독을 위한 아기걸음 2k-ary 성인걸음 알고리즘)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.2
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    • pp.23-29
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    • 2015
  • The baby-step giant-step algorithm seeks b in a discrete logarithm problem when a,c,p of $a^b{\equiv}c$(mod p) are already given. It does so by dividing p by m block of $m={\lceil}{\sqrt{p}}{\rceil}$ length and letting one giant walk straight toward $a^0$ with constant m strides in search for b. In this paper, I basically reduce $m={\lceil}{\sqrt{p}}{\rceil}$ to p/l, $a^l$ > p and replace a giant with an adult who is designed to walk straight with constant l strides. I also extend the algorithm to allow $2^k$ adults to walk simultaneously. As a consequence, the proposed algorithm quarters the execution time of the basic adult-walk method when applied to $2^k$, (k=2) in the range of $1{\leq}b{\leq}p-1$. In conclusion, the proposed algorithm greatly shorten the step number of baby-step giant-step.

STK Feature Tracking Using BMA for Fast Feature Displacement Convergence (빠른 피쳐변위수렴을 위한 BMA을 이용한 STK 피쳐 추적)

  • Jin, Kyung-Chan;Cho, Jin-Ho
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.8
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    • pp.81-87
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    • 1999
  • In general, feature detection and tracking algorithms is classified by EBGM using Garbor-jet, NNC-R and STK algorithm using pixel eigenvalue. In those algorithms, EBGM and NCC-R detect features with feature model, but STK algorithm has a characteristics of an automatic feature selection. In this paper, to solve the initial problem of NR tracking in STK algorithm, we detected features using STK algorithm in modelled feature region and tracked features with NR method. In tracking, to improve the tracking accuracy for features by NR method, we proposed BMA-NR method. We evaluated that BMA-NR method was superior to NBMA-NR in that feature tracking accuracy, since BMA-NR method was able to solve the local minimum problem due to search window size of NR.

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A Segment Algorithm for Extracting Item Blocks based on Mobile Devices in the Web Contents (웹 콘텐츠에서 모바일 디바이스 기반 아이템 블록을 추출하기 위한 세그먼트 알고리즘)

  • Kim, Su-Do;Park, Tae-Jin;Park, Man-Gon
    • Journal of Korea Multimedia Society
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    • v.12 no.3
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    • pp.427-435
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    • 2009
  • Users are able to search and read interesting items and hence click hyperlink linked to the item which is detailed content unit such as menu, login, news, video, etc. Small screen like mobile device is very difficult to viewing all web contents at once. Browsing and searching for interesting items by scrolling to left and right or up and down is discomfort to users in small screen. Searching and displaying directly the item preferred by users can reduces difficulty of interface manipulation of mobile device. To archive it, web contents based on desktop will be segmented on a per-item basis which component unit of web contents. Most segment algorithms are based on segment method through analysis of HTML code or mobile size. However, it is difficult to extract item blocks. Because present web content is getting more complicated and diversified in structure and content like web portal services. A web content segment algorithm suggested in this paper is based on extracting item blocks is component units of web contents.

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The Extraction of Fingerprint Corepoint And Region Separation using Labeling for Gate Security (출입 보안을 위한 레이블링을 이용한 영역 분리 및 지문 중심점 추출)

  • Lee, Keon-Ik;Jeon, Young-Cheol;Kim, Kang
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.6
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    • pp.243-251
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    • 2008
  • This study is to suggest the extraction algorithms of fingerprint corepoint and region separation using the labeling for gate security in order that it might be applied to the fingerprint recognition effectively. The gate security technology is entrance control, attendance management, computer security, electronic commerce authentication, information protection and so on. This study is to extract the directional image by dividing the original image in $128{\times}128$ size into the size of $4{\times}4$ pixel. This study is to separate the region of directional smoothing image extracted by each directional by using the labeling, and extract the block that appeared more than three sorts of change in different directions to the corepoint. This researcher is to increase the recognition rate and matching rate by extracting the corepoint through the separation of region by direction using the maximum direction and labeling, not search the zone of feasibility of corepoint or candidate region of corepoint used in the existing method. According to the result of experimenting with 300 fingerprints, the poincare index method is 94.05%, the proposed method is 97.11%.

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Architecture and Hardwarw Implementation of Dynamic GSMP V3 with Dynamic Buffer Management Scheme (동적 버퍼관리 방식의 Dynamic GSMP V3의 구조와 하드웨어 구현)

  • Kim, Young-Chul;Lee, Tae-Won;Kim, Kwang-Ok
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.38 no.8
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    • pp.30-41
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    • 2001
  • In this paper, the architecture of Dynamic GSMP V3(General Switch Management Protocol Version 3), an open interface protocol with resource management functions for efficient IP service on ATM over MPLS, is proposed and implemented in hardware. And we compare and analyze the proposed GSMP with the GSMP under standardization process in terms of CLR (Cell Loss Rate). We design the Slave block of the Dynamic GSMP V3 using SAM-SUNG SoG $0.5{\mu}m$ process, which performs functions for switch connection control in the ATM Switch. In order to compare difference performanaces between the proposed method and the conventional one, we conducts simulations using the minimum buffer search algorithm with random cell generation. The exponential results show that the proposed method leads to performance enhancement in CLR.

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VLSI Design of H.264/AVC CAVLC encoder for HDTV Application (실시간 HD급 영상 처리를 위한 H.264/AVC CAVLC 부호화기의 하드웨어 구조 설계)

  • Woo, Jang-Uk;Lee, Won-Jae;Kim, Jae-Seok
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.7 s.361
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    • pp.45-53
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    • 2007
  • In this paper, we propose an efficient hardware architecture for H.264/AVC CAVLC (Context-based Adaptive Variable Length Coding) encoding. Previous CAVLC architectures search all of the coefficients to find statistic characteristics in a block. However, it is unnecessary information that zero coefficients following the last position of a non-zero coefficient when CAVLC encodes residual coefficients. In order to reduce this unnecessary operation, we propose two techniques, which detect the first and last position of non-zero coefficients and arrange non-zero coefficients sequentially. By adopting these two techniques, the required processing time was reduced about 23% compared with previous architecture. It was designed in a hardware description language and total logic gate count is 16.3k using 0.18um standard cell library Simulation results show that our design is capable of real-time processing for $1920{\times}1088\;30fps$ videos at 81MHz.

DEVS Modeling with Hierarchical Planning: HRG-DEVS (계층적 계획을 이용한 이산 사건 시뮬레이션 모델링: HRG-DEVS)

  • Yi, Mi-Ra
    • Journal of the Korea Society for Simulation
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    • v.15 no.2
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    • pp.1-12
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    • 2006
  • As the needs of intelligent systems increase, there have been diverse approaches that combine artificial intelligence (AI) and simulation in the last decade. RG-DEVS, which is the basis for this paper, embedded AI planning techniques into the simulation modeling methodology of DEVS, in order to specify dynamically a simulation model. However, a hierarchy concept, which is used for various types of problem solving systems. is not included in the planning of RG-DEVS. The hierarchy concept reduces the computational cost of planning by reducing the search space, and also makes it easy to apply the hierarchical process flow of a target system to planning. This paper proposes Hierarchical RG-DEVS (HRG-DEVS) in an attempt to insert hierarchical planning capability into RG-DEVS. For the verification of the proposed modeling methodology, HRG-DEVS is applied to model the block's world problem of ABSTRIPS, which is a classical planning problem.

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A Study of Network Forensics related to Internet Criminal at UCC (UCC와 관련된 인터넷 범죄에 대한 네트워크 포렌식 연구)

  • Lee, Gyu-An;Park, Dea-Woo;Shin, Young-Tae
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.2
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    • pp.143-151
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    • 2008
  • 74% of Internet users use the UCC, and You Tube using firearms in a crime occurred. Internet crime occurred in the online, non-face transaction, anonymous, encapsulation. In this paper, we are studied a Network Forensic Way and a technique analyze an aspect criminal the Internet haying appeared at Internet UCC, and to chase. Study ID, IP back-tracking and position chase through corroborative facts collections of the UCC which used UCC search way study of the police and a public prosecutor and storage way and network forensic related to crimes of Internet UCC. Proof data encrypt, and store, and study through approach control and user authentication so that they are adopted to legal proof data through integrity verification after transmission and storages. This research via the Internet and criminal conspiracy to block the advance promotion, and for the criminal investigative agencies of the Internet will contribute to the advancement forensics research.

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A Study on the Shape-Based Motion Estimation For MCFI (MCFI 구현을 위한 형태 기반 움직임 예측에 관한 연구)

  • Park, Ju-Hyun;Kim, Young-Chul;Hong, Sung-Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.3C
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    • pp.278-286
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    • 2010
  • Motion Compensated Frame Interpolation(MCFI) has been used to reduce motion jerkiness for dynamic scenes and motion blurriness for LCD-panel display as post processing for large screen and full HD(high definition) display. Conventionally, block matching algorithms (BMA) are widely used to do motion estimation for simplicity of implementation. However, there are still several drawbacks. So in this paper, we propose a novel shape-based ME algorithm to increase accuracy and reduce ME computational cost. To increase ME accuracy, we do motion estimation based on shape of moving objects. And only moving areas are included for motion estimation to reduce computational cost. The results show that the computational cost is 25 % lower than full search BMA, while the performance is similar or is better, especially in the fast moving region.

Automated Method for Detecting OOB Vulnerability of Heap Memory Using Dynamic Symbolic Execution (동적 기호 실행을 이용한 힙 메모리 OOB 취약점 자동 탐지 방법)

  • Kang, Sangyong;Park, Sunghyun;Noh, Bongnam
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.28 no.4
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    • pp.919-928
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    • 2018
  • Out-Of-Bounds (OOB) is one of the most powerful vulnerabilities in heap memory. The OOB vulnerability allows an attacker to exploit unauthorized access to confidential information by tricking the length of the array and reading or writing memory of that length. In this paper, we propose a method to automatically detect OOB vulnerabilities in heap memory using dynamic symbol execution and shadow memory table. First, a shadow memory table is constructed by hooking heap memory allocation and release function. Then, when a memory access occurs, it is judged whether OOB can occur by referencing the shadow memory, and a test case for causing a crash is automatically generated if there is a possibility of occurrence. Using the proposed method, if a weak block search is successful, it is possible to generate a test case that induces an OOB. In addition, unlike traditional dynamic symbol execution, exploitation of vulnerabilities is possible without setting clear target points.