• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.5B
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• pp.554-560
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• 2001

통신망의 급격한 발전과 통신 속도의 향상에 따라 암호 알고리듬의 고속화 필요성이 절실하다. 본 논문에서는 LFSR을 고속화하기 위하여 한 클럭에 m번의 이동이 이루어지는 고속 병렬형 PS-LFSR을 제안하였고, 이를 기본으로 다수의 키 수열 발생기를 병렬 연결하여 속도를 개선시킨 병렬형 스트림 암호를 제안하였다. 그리고 병렬형 스트림 암호 예로서 m-병렬 합산 수열 발생기(m-parallel SUM-BSG)를 제안하여 m=8인 병렬 발생기를 세부 설계 예시하였으며, 제안된 발생기는 기존의 비도 수준을 유지하면서 처리 속도를 m배 높을 수 있음을 확인하였다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.399-405
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• 2003

A new type of signature scheme, called NTRUSign, based on solving the approximately closest vector problem in an NTRU lattice was proposed in［7］,［8］. However no security proof against chosen messages attack has been made for this scheme. In this paper, we show that NTRUSign signature scheme contains the weakness of malleability. From this, one can derive new valid signatures from any previous message-signature pair which means that NTRUSign is not secure against strongly existential forgery.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7B
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• pp.1050-1057
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• 2010

Nowadays, the network attack occurs frequently. At the same time, the inbound network is also attacked. Even though the security system has been continuously developed in order to prevent from attacks, the network performance is sacrificed for the network security. Therefore, a security system which obtains performance and security together is urgently needed. In this paper, an arrangement of functional firewall and a secure clustering methodology, obtained from distributing functions of a conventional firewall, are proposed based on the idea that performance and security should be obtained together.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1996.11a
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• pp.326-335
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• 1996

In this paper, we quantify the tradeoff between security and performance in secure data communication systems based on the queueing theory, and propose the optimization methods, such as the preprocessing, a message segmentation, compression, integration of compression and encryption and integration of user authentication and access control, which are able to reduce the delay induced by the security mechanisms and protocols. Moreover, we analyze the average delay for the secure data communication systems through the computer simulations, which are modeled by M/M/1, M/E$_2$/1 and M/H$_2$/1 queueing systems, respectively. We consider the DES, RSA digital signature and the combination of IDEA and RSA as security mechanisms for applying security services.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.718-720
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• 1999

Chua's circuit is a simple electronic network which exhibits a variety of bifurcation and attractors. The circuit consists of two capacitors, an inductor, a linear resistor. and a nonlinear resistor. In this paper, a transmitter and a receiver using two identical Chua's circuits are proposed and a equivalent wire secure communications are investigated. A secure communication method in which the desired information signal is synthesized with the chaos signal created by the Chua's circuit is proposed and information signal is demodulated also using the Chua's circuit. The proposed method is synthesizing the desired information with the chaos circuit by adding the information signal to the chaos signal in the wire transmission system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.166-169
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• 2000

Chua's circuit is a simple electronic network which exhibits a variety of bifurcati on and attractors. The circuit consists of two capacitors, an inductor, a linear resistor, and a nonlinear resistor. In this paper, a transmitter and a receiver using two identical Chua's circuitsare proposed and a transmission secure communications are investigated. A secure communication method in which the desired information signal is synthesized with the chaos signal created by the Chua's circuit is proposed and information signal is demodulated also using the Chua's circuit. The proposed method is synthesizing the desired information with the chaos circuit by adding the information signal to the chaos signal in the power lime.

• Convergence Security Journal
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• v.5 no.4
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• pp.49-58
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• 2005

We propose a specific ubiquitous sensor network (USN) architecture as a promising candidate of the future telemedicine model which offers the patient's mobility and more cost-efficient medical care system. This new USN architecture is a kind of cell-based secure sensor network supporting encrypted multi-casting communications and it has a hybrid routing protocol by adapting flat routing to hierarchical routing. For the patient's privacy and the protection of patient's vital information from eavesdropping, we adopt a lightweight PKI-based secure communication protocol with some formal presentation on its core procedure.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2407-2409
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• 2000

Chua's circuit is a simple electronic network which exhibits a variety of bifurcation and attractors. The circuit consists of two capacitors, an inductor, a linear resistor, and a nonlinear resistor. In this paper, a transmitter and a receiver using two identical Chua's circuits are proposed and a equivalent T type wire secure communications are investigated. A secure communication method in which the desired information signal is synthesized with the chaos signal created by the Chua's circuit is proposed and information signal is demodulated also using the Chua's circuit. The proposed method is synthesizing the desired information with the chaos circuit by adding the information signal to the chaos signal in the wire transmission system.

• Journal of Convergence Society for SMB
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• v.4 no.4
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• pp.19-23
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• 2014

Group communication is becoming increasingly popular in Internet applications such as videoconferences, online chatting programs, games, and gambling. For secure communications, the integrity of messages, member authentication, and confidentiality must be provided among group members. To maintain message integrity, all group members use the Group Key (GK) for encrypting and decrypting messages while providing enough security to protect against passive attacks. Tree-based Group Diffie-Hellman (TGDH) is an efficient group key agreement protocol to generate the GK. TGDH assumes all members have an equal computing power. One of the characteristics of distributed computing and grid environments is heterogeneity; the member can be at a workstation, a laptop or even a mobile computer. Member reordering in the TDGH protocol could potentially lead to an improved protocol; such reordering should capture the heterogeneity of the network as well as latency. This research investigates dynamic reordering mechanisms to consider not only the overhead involved but also the scalability of the proposed protocol.

• Journal of Communications and Networks
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• v.15 no.1
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• pp.1-7
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• 2013

Most of the provably-secure proxy signature schemes rely on the average-case hardness problems such as the integer factorization problems and the discrete logarithm problems. Therefore, those schemes are insecure to quantum analysis algorithms, since there exist quantum algorithms efficiently solving the factorization and logarithm problems. To make secure proxy signature schemes against quantum analysis, some lattice-based proxy signature schemes are suggested. However, none of the suggested lattice-based proxy signature schemes is proxy-protected in the adaptive security model. In the paper, we propose a provably-secure ID-based proxy signature scheme based on the lattice problems. Our scheme is proxy-protected in the adaptive security model.