• 한국컴퓨터산업학회논문지
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• 제5권9호
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• pp.1069-1078
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• 2004

본 논문에서는 광 시각 암호기술에 근거한 개인 정보보호 방식을 제안하였다. 실험에 사용된 지문 데이터는 광 시각 암호 기술과 개방형 네트워크를 통해 전달된 공유 데이터의 일부를 고려한 secret sharing 방법에 의해 처리되었다. 필요에 따라 한 개인은 자신의 지문을 다른 공유 정보에 제공하는 방식으로 본인의 것을 확인할 수 있다. 다양한 환경 조건에서도 어려움 없이 효과적으로 지문을 인식 할 수 있음을 실험을 통해 검증하였다.

• 인터넷정보학회논문지
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• 제7권3호
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• pp.83-91
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• 2006

본 논문에서는 인증서를 사용하는 모든 암호시스템 분야에 응용될 수 있는 인증 및 키 복원 프로토콜로 PKINIT를 응용한 안전한 초기인증 공개키 암호시스템 모델을 연구하였다. 멤버들에 대한 인증은 서버와 사용자간에 인증서를 기반으로 공개 키 암호에 의한 초기인증과 세션 키 분배, 응용자원 서버들과의 비밀통신에서 키의 유실을 고려한 키 복구지원 프로토콜을 제안하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 추계학술대회
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• pp.627-628
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• 2010

2002년 S.Chow는 AES 암호 알고리즘을 화이트박스 공격에 강하게 구현하는 방법으로 화이트박스 AES(이하 WBC-AES) 암호를 제안하였다. 본 논문에서는 S.Chow가 제안한 WBC-AES에 대한 설명과 함께 이를 이용하여 콘텐츠를 보호하기 위한 방법에 관하여 기술하고자 한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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• pp.144-147
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• 2000

Data security is an important issue in today's computer networks. In order to construct a safe infra in the open communication network, a cryptography is necessarily applied to several communication application fields like a high-speed networking system supporting real-time operation. A cryptography which has already realized by a software is designed by using a hardware to improve a throughput. In this paper, we design hardware architecture of IDEA by using a single iterative round method to improve a encryption throughput. In addition, we intend to develop a hardware design methodology that a specific cryptography operate with high-speed. The hardware model is described in VHDL and synthesized by the Samsung KG 80 Library in the Synopsys development software tool. With a system clock frequency 20MHz, this hardware permits a data conversion rate of more than 116 Mbit/s.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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• pp.321-324
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• 2000

In this paper, we proposed a new visual cryptography scheme based on optical interference which improves the contrast and SNR of reconstructed images comparing with conventional visual cryptography method. We divided an binary image to be encrypted into n slides. To encrypt them, (n-1) random independent keys and one another random key by XOR process between four random keys were prepared. XOR between each divided image and each random key makes encrypted n encrypted images. From these images, encrypted binary phase masks can be made. For decryption all of phase masks should be placed together in the interferometer such as Mach-Zehnder interferometer.

• Journal of the Optical Society of Korea
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• 제20권1호
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• pp.55-63
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• 2016

In this paper, a new asymmetric public key cryptography based on the modified RSA algorithm is proposed by using logic-based optical processing. The proposed asymmetric public key algorithm is realized into an optical schematic, where AND, OR and XOR logic operations are implemented by using free space digital optics architecture. Schematically, the proposed optical configuration has an advantage of generating the public keys simultaneously. Another advantage is that the suggested optical setup can also be used for message encryption and decryption by simply replacing data inputs of SLMs in the optical configuration. The last merit is that the optical configuration has a 2-D array data format which can increase the key length easily. This can provide longer 2-D key length resulting in a higher security cryptosystem than the conventional 1-D key length cryptosystem. Results of numerical simulation and differential cryptanalysis are presented to verify that the proposed method shows the effectiveness in the optical asymmetric cryptographic system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권7호
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• pp.3401-3420
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• 2018

Pixel expansion and contrast are two major performance parameters for visual cryptography scheme (VCS), which is a type of secret image sharing. Random Grid (RG) is an alternative approach to solve the pixel expansion problem. Chen and Tsao proposed the first (k, n) RG-based VCS, and then Guo et al., Wu et al., Shyu, and Yan et al. significantly improved the contrast in recent years. However, the investigations on improving the contrast of threshold RG-based VCS are not sufficient. In this paper, we develop a contrast-improved algorithm for (k, n) RG-based VCS. Theoretical analysis and experimental results demonstrate that the proposed algorithm outperformers the previous threshold algorithms with better visual quality and a higher accuracy of contrast.

• Journal of information and communication convergence engineering
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• 제14권4호
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• pp.233-239
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• 2016

A remote control system (RCS) can monitor a user's confidential information by using the broadcast receivers in Android OS. However, the current RCS detection methods are based only on a virus vaccine. Therefore, if the user's smartphone is infected by a brand new RCS, these methods cannot detect this new RCS immediately. In this paper, we present a secure message transmission medium. This medium is completely isolated from networks and can communicate securely through a QR code channel by using symmetric key cryptography such as the AES block cipher and public key cryptography such as elliptic curve cryptography for providing security. Therefore, the RCS cannot detect any confidential information. This approach is completely immune to any RCS attacks. Furthermore, we present a secure QR code-based key exchange protocol by using the elliptic curve Diffie-Hellman method and message transmission protocols; the proposed protocol has high usability and is very secure.

• 한국IT서비스학회지
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• 제3권2호
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• pp.99-104
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• 2004

Conventional and public-key cryptography has been widely accepted as a base technology for the design of computer security systems. D-classes have the potential for application to conventional and public-key cryptography. However, there are very few results on D-classes because the computational complexity of D-class computation is NP-complete. This paper discusses the design of algorithms for the efficient computation of D-classes and the Java implementation of them. In addition, the paper implements the same D-class computation algorithms in C and shows the performance of C and Java programming languages for the computation-intensive applications by comparing their execution results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권7호
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• pp.2862-2878
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• 2020

Data Security is the most challenging area in Internet communication, where most of the secret sharing schemes are proposed for binary images. But still it lacks in providing security for data communication, especially in image transmission. Traditional visual cryptography scheme generate meaningless diwies and the reconstruction phase leads to quality degradation over the secret image. In this work, an intelligent two dimensional secret share construction scheme is proposed. A secret image is expanded into n diwies with the choice of scheme selection. By Stacking all the qualified diwies to revert the secret image without content loss and less than s^* - 1 shares could not reveal any information about the secret image. The experimental results emphasize that the proposed secret share scheme is highly secured for image transmission.