• Title/Summary/Keyword: Dynamic Shuffling

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A Study on Video Data Protection Method based on MPEG using Dynamic Shuffling (동적 셔플링을 이용한 MPEG기반의 동영상 암호화 방법에 관한 연구)

  • Lee, Ji-Bum;Lee, Kyoung-Hak;Ko, Hyung-Hwa
    • Journal of Korea Multimedia Society
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    • v.10 no.1
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    • pp.58-65
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    • 2007
  • This dissertation proposes digital video protection algorithm lot moving image based on MPEG. Shuffling-based encryption algorithms using a fixed random shuffling table are quite simple and effective but vulnerable to the chosen plaintext attack. To overcome this problem, it is necessary to change the key used for generation of the shuffling table. However, this may pose a significant burden on the security key management system. A better approach is to generate the shuffling table based on the local feature of an image. In order to withstand the chosen plaintext attack, at first, we propose a interleaving algorithm that is adaptive to the local feature of an image. Secondly, using the multiple shuffling method which is combined interleaving with existing random shuffling method, we encrypted the DPCM processed 8*8 blocks. Experimental results showed that the proposed algorithm needs only 10% time of SEED encryption algorithm and moreover there is no overhead bit. In video sequence encryption, multiple random shuffling algorithms are used to encrypt the DC and AC coefficients of intra frame, and motion vector encryption and macroblock shuffling are used to encrypt the intra-coded macroblock in predicted frame.

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Directed Evolution in Protein Functionality Improvement (단백질 기능 향상을 위한 방향적 진화)

  • 강환구;김학성
    • KSBB Journal
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    • v.16 no.2
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    • pp.107-114
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    • 2001
  • The dynamic evolution process has resulted in the myriad shapes, functions, and systems evident in every living organism. For centuries, people have been harnessing the power of evolution to produce new varieties of plants and animals, such as producing tomatoes from berries and Chihuahuas from wolves. Now scientists are using it to produce better molecules, ranging from drugs to industrial chemicals, and doing it in days or weeks rather than eons. The ingenious process, which creates genetic diversity and selects those with desired features in the laboratory, is called directed evolution or test tube evolution. In this paper, concepts of directed molecular evolution and some examples will be discussed.

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