• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.5
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• pp.88-98
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• 2011

Recently, according as the importance of GIS(geography information system) database security is embossed, much researches had been achieved about GIS network security. But most such researches are weak against sourceful illegal reproductions and distributions of GIS vector data map. In this paper, we proposed an efficient layer unit contents based partial encryption technique in the vector map compression domain to prevent illegal distributions and unauthorized accesses. This method achieves a partial encryption about each central coordinate and directional parameters of a MCA(minimum coding attribute) that is created at the vector map compression processing in the vector space. First, the position encryption is applied as permutating randomly the center coordinate of each record that is minimum unit of vector map shape. And second, the direction encryption that changing shapes of vector map topography is applied as encrypting the direction of vertices's coordinates of each record. In experimental results, we confirmed that our proposed method can encipher the large volumed vector map data effectively in low computational complexity. Also, we could minimize the decline of compression efficiency that occurred by conventional contents based encryption schemes using AES or DES algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.3
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• pp.603-611
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• 2013

In this paper, we propose a new method which estimates and encrypts significant component of digital image such as digital cinema using discrete wavelet packet transform (DWPT). After analyzing the characteristics of images in spatial and frequency domain, the required information for ciphering an image was extracted. Based on this information an ciphering method was proposed with wavelet transform and packetization of subbands. The proposed algorithm can encrypt images in various robust from selecting transform-level and energy threshold. From analyzing the encryption effect numerically and visually, the optimized parameter for encryption is presented. Without additional analyzing process, one can encrypt efficiently digital image using the proposed parameter. Although only 0.18% among total data is encrypted, the reconstructed image dose not identified. The paketization information of subbands and the cipher key can be used for the entire secret key.

• Journal of Korea Society of Industrial Information Systems
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• v.8 no.3
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• pp.85-90
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• 2003

This paper proposes a modular multiplier based on LFSR (Linear Feedback Shift Register) architecture with efficient area complexity over GF(2/sup m/). At first, we examine the modular exponentiation algorithm and propose it's architecture, which is basic module for public-key cryptosystems. Furthermore, this paper proposes on efficient modular multiplier as a basic architecture for the modular exponentiation. The multiplier uses AOP (All One Polynomial) as an irreducible polynomial, which has the properties of all coefficients with '1 ' and has a more efficient hardware complexity compared to existing architectures.

• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.264-266
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• 2008

정보화 사회의 발전에 따라 컴퓨터끼리의 커뮤니케이션을 넘어 물리공간을 융합하는 유비쿼터스 기술이 발전하고 있다. 유비쿼터스를 위한 기술인 RFID는 RFID TAG가 모든 물체에 부착되어 리더와 정보를 주고받을 수 있게 된다. 하지만 RFID의 제한적인 환경으로 인해 현재 보편적으로 쓰이는 보안 기술을 사용하는 것이 어렵게 되어 유비쿼터스 시대에 맞는 새로운 보안 방법의 연구가 필요하다. 본 논문에서는 유비쿼터스 시대에 맞는 암호화 인증 기술에 방법에 대하여 연구하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7C
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• pp.663-670
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• 2009

In this paper, we propose the image encryption method which gradually uses NFSR(Non-linear Feedback Shift Register) and 20 CAT(Two-Dimensional Cellular Automata Transform). The encryption method is processed in the following order. First, NFSR is used to create a PN(pseudo noise) sequence, which matches the size of the original image. Then, the created sequence goes through a XOR operation with the original image and process the encipherment. Next, the gateway value is set to produce a 20 CAT basis function. The produced basis function is multiplied by encryption image that has been converted to process the 20 CAT encipherment. Lastly, the results of the experiment which are key space analysis, entropy analysis, and sensitivity analysis verify that the proposed method is efficient and very secure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11C
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• pp.905-916
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• 2008

In this paper, we propose a new method which estimates and encrypts significant component of digital hologram using discrete wavelet packet transform (DWPT). After analyzing the characteristics of digital hologram in spatial and frequency domain, the required information for ciphering digital hologram was extracted. Based on this information an ciphering method was proposed with wavelet transform and packetization of subbands. The proposed algorithm can encrypt digital hologram in various robust from selecting transform-level and energy threshold. From analyzing the encryption effect numerically and visually, the optimized parameter for encryption is presented. Without additional analyzing process, one can encrypt efficiently digital hologram using the proposed parameter. Although only 0.032% among total data is encrypted, the reconstructed object dose not identified. The paketization information of subbands and the cipher key can be used for the entire secret key.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.626-629
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• 2020

인터넷의 발전으로 웹 서비스를 사용하는 사용자가 기하급수적으로 늘어났고 사용자에게 다양한 서비스를 제공하기 위해 많은 기술이 등장하고 있다. 서비스를 받는 사용자의 웹브라우저에서도 서버의 많은 기술을 구현할 수 있는 공간을 제공하고 있는데 바로 Web Storage와 Indexed DB이다. Web Storage는 용도에 따라 수 MB 정도를 사용하지만 많은 양의 데이터를 구조화하여 사용한다면 Indexed DB가 적합하다. 하지만 Web Storage뿐만 아니라 Indexed DB 역시 영속적이고 평문의 데이터를 저장하고 있다. 이러한 데이터는 웹 보안에 취약하여 XSS 등의 공격에 사용자의 데이터가 노출되어 탈취되거나 편집되어 악용될 우려가 매우 크다. 본 논문에서는 이와 같은 취약점을 보완하기 위해 운영체제와 디바이스 정보를 이용하여 사용자를 인증하고 암호화하는 기법을 구현하여 성능평가를 하였다.

• Korean Journal of Optics and Photonics
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• v.17 no.6
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• pp.507-513
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• 2006

In this paper, we propose an improved image encryption and fault-tolerance decryption method using phase wrapping and phase encoding in the frequency domain. To generate an encrypted image, an encrypting key which denotes the product of a phase-encoded virtual image, not an original image, and a random phase image is zero-padded and Fourier transformed and its real-valued data is phase-encoded. The decryption process is simply performed by performing the inverse Fourier transform for multiplication of the encrypted key with the decrypting key, made of the proposed phase wrapping method, in the output plane with a spatial filter. This process has the advantages of solving optical alignment and pixel-to-pixel mapping problems. The proposed method using the virtual image, which does not contain any information from the original image, prevents the possibility of counterfeiting from unauthorized people and also can be used as a current spatial light modulator technology by phase encoding of the real-valued data. Computer simulations show the validity of the encryption scheme and the robustness to noise of the encrypted key or the decryption key in the proposed technique.

• Journal of Korea Spatial Information System Society
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• v.3 no.2 s.6
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• pp.53-61
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• 2001

The GIS Network consists of the Clearinghouse Network Gateway and Clearinghouse Node and Geo-spatial Data Server. Recently with the development of Information and Network technologies, GIS Network should be needed to be more secure than ever. In this paper, we proposed the effective access control method for the distributed GIS network. PKI (Public Key Infrastructure) Technologies are used for access control and security for transmission on Geo-spatial data

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.699-702
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• 2005

최근 컴퓨터 성능과 네트워크 속도의 발전은 다양한 형태의 데이터를 유선 혹은 무선 환경상에서 주고 받고 처리할 수 있게 해주고 있다. 또한 일차원적인 텍스트, 이미지, 음성, 동영상뿐만 아니라 다차원 형태의 공간 데이터도 다양한 형태의 서비스로 제공되고 있다. 하지만 공간 데이터에 대한 연구는 공간 데이터 표준, 서비스, 성능적인 측면에 대한 연구만 진행이 되었을 뿐 보안적인 측면에 대한 연구는 미비한 상태이다. 이에 XML 의 보안 기법을 공간 데이터에 적용하여 공간 데이터 자체에 대한 보안 레벨과 암호화를 적용하여 공간 데이터 전송을 위한 보안구조를 제시하고자 한다.