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Optical Visual Cryptography using the Characteristics of Spatial Light Modulation

공간광변조 특성을 이용한 광비쥬얼 크립토그래피

  • Yi, Sang-Yi (National Security Research Institute) ;
  • Wi, Sung-Min (College of Electronics and Information Engineering, Kwangwoon University) ;
  • Lee, Seung-Hyun (College of Electronics and Information Engineering, Kwangwoon University) ;
  • Yoo, Ji-Sang (College of Electronics and Information Engineering, Kwangwoon University) ;
  • Kim, Dong-Wook (College of Electronics and Information Engineering, Kwangwoon University)
  • Published : 2007.06.25

Abstract

Optical visual cryptography (OVC) based on binary computer generated holograms (BCGH) is proposed. OVC used optics instead of human eyesight for decryption of visual cryptography (VC). As a result, it was possible to adapt cryptography to an optical system. However, it also had some difficulties because it did not overcome the existing problems of VC completely. This paper suggests a method of optical cryptography implementation based on the phase modulation characteristics of a liquid crystal display (LCD). The problems are evaluated by simulation. This system shows that the noise is reduced and resolution is improved compared with the conventional OVC.

비쥬얼 크립토그래피(VC)의 복호 시스템으로써 인간의 시각을 대신하여 광학계를 사용하는 이진 컴퓨터형성홀로그램(BCGH) 기반의 광 비쥬얼 크립토그래피(OVC)가 제안되어 광학 시스템에 크립토그래피를 적용할 수 있게 되었으나 VC의 문제점을 극복하는 과정에서 또 다른 문제를 발생하였다. 본 논문에서는 공간광변조기의 위상변조 특성을 이용하여 광 크립토그래피를 구현하는 방법을 제시하고 시뮬레이션을 통하여 구현상의 문제점 및 타당성을 도출하였다. 제안한 광 크립토그래피는 액정디스플레이(LCD)를 활용하여 OVC로서 유용한 결과를 얻도록 하였으며, 기존 시각 암호에서 근본적으로 해결이 불가능하였던 해상도와 잡음 문제를 개선하였다.

Keywords

References

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