• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.44 no.3
• /
• pp.45-50
• /
• 2007

We present a auto compensating quantum key distribution system based on optical fiber at 1550nm. In the quantum key transmission system, main control board and phase modulation driving board are fabricated for auto controlling quantum key distribution(QKD). We tested the single photon counts per dark counts for a single photon detector, quantum key distribution rate($R_{sift}$) and the quantum bit error rate (QBER). Quantum bit error rate of 3.5% in 25km QKD is obtained. This system is commercially available.

• The KIPS Transactions:PartC
• /
• v.19C no.1
• /
• pp.39-46
• /
• 2012

In this paper, we propose a key distribution scheme for flexible chipset pairing conditional access system. Chipset pairing conditional access system is the implementation of CA (Conditional Access) module by using both embedded secure chip in a Set-Top Box(STB) and smartcard, and the secure chip embedded in a STB forms a secure channel between the smartcard and the STB. In short, it is the system that a smartcard outputs encrypted CW (Control Word) to the STB, and the STB decrypts an encrypted CW by using the embedded secure chip. The drawback of this chipset pairing conditional access system is that one smartcard is able to be used for only one specified STB since it is the system using the STB bound to a smartcard. However, the key distribution scheme proposed in this paper overcomes a drawback of current chipset pairing conditional access system by using Chinese Remainder Theorem(CRT). To be specific, with this scheme, one smartcard can be used for multiple, not single, STBs, and applied to current chipset pairing without great changes.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 1991.11a
• /
• pp.49-57
• /
• 1991

Several variants of the Diffie-Hellman public key distribution are examined, and a simple and relatively secure public key distribution protocol is introduced. Using a normal basis of GF(2$^{m}$ ), this protocol is implemented, and simulated in software. A program is developed, whereby a normal basis is effectively searched for fast multiplication in GF(2$^{m}$ ).

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.1 no.1
• /
• pp.38-46
• /
• 1991

This paper pro poses a ley distribution system based on identification information. The system uses an indivdual user's identification instead of the public file used in the Diffie-Hellman sustem. It does not require any services of a center to distribute work keys and users to keep directory public file. We propose an identity-based key distribution system for generating a commom secret conference kdy for two or more users. We assume users are connected in a ring network. Message among users authenticated using each user's identification informa-tion. The security of the our proposed system is based on the difficulty of both factoring large numbers and computing discrete logarithms over large finite fields.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.12 no.2
• /
• pp.123-133
• /
• 2002

In Network Environment, Kerberos certification mechanism to require Kerberos server in other area unconditionally belief. Also, Kerberos server in cooperation area must be share server of other area and secret key. To solve these two problems, this paper proposed safe security mechanism of doing to ably IETF CAT's PKINIT/PKCROSS a1gorithm with Public Key Infrastructure and use Directory System and service between realms do trust and prove each Kerberos trust center base. Also, Although Kerberos server of each area must be foreknowing each server's secret key and public key, Obtain through Trust center and acquire each area's public key and common symmetric key, Application server excluded process that must register key in Key Distribution Center.

• Electronics and Telecommunications Trends
• /
• v.33 no.6
• /
• pp.94-106
• /
• 2018

A quantum key distribution (QKD) provides in principle an unconditional secure communication unlike the standard public key cryptography depending on the computational complexity. In particular, free-space QKD can give a secure solution even without a fiber-based infrastructure. In this paper, we investigate an overview of recent research trends in the free-space QKD system, including satellite and handheld moving platforms. In addition, we show the key components for a free-space QKD system such as the integrated components, single photon detectors, and quantum random number generator. We discuss the technical challenges and progress toward a future free- space QKD system and components.

• The KIPS Transactions:PartA
• /
• v.11A no.2
• /
• pp.175-180
• /
• 2004

Generally, as for the multimedia high quality contents, an illegality facsimile is possible without a damage of a quality. Also a distribution of contents duplicated illegality in an Internet is giving a great economic loss to digital contents provider. Therefore, a study for security and efficient distribution of digital contents is required. The most important issues in a design of digital contents distribution system are a user convenience, an execution speed and a security. In this study, we designed digital contents distribution system that used a web caching technology and an encryption/decryption technique on hierarchical structure. The proposed system was the digital contents distribution system that improved a security and execution speed, a convenience of a user. Also it verified performance superiority of a proposed system by an examination.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.2
• /
• pp.433-440
• /
• 2014

In this study, a method for the low-carbon active distribution system (ADS) planning is proposed. It takes into account the impacts of both network capacity and demand correlation to the renewable energy accommodation, and incorporates demand response (DR) as an available resource in the ADS planning. The problem is formulated as a mixed integer nonlinear programming model, whereby the optimal allocation of renewable energy sources and the design of DR contract (i.e. payment incentives and default penalties) are determined simultaneously, in order to achieve the minimization of total cost and $CO_2$ emissions subjected to the system constraints. The uncertainties that involved are also considered by using the scenario synthesis method with the improved Taguchi's orthogonal array testing for reducing information redundancy. A novel cuckoo search (CS) is applied for the planning optimization. The case study results confirm the effectiveness and superiority of the proposed method.

• Journal of Information Science Theory and Practice
• /
• v.10 no.spc
• /
• pp.123-134
• /
• 2022

Existing network cryptography systems are threatened by recent developments in quantum computing. For example, the Shor algorithm, which can be run on a quantum computer, is capable of overriding public key-based network cryptography systems in a short time. Therefore, research on new cryptography systems is actively being conducted. The most powerful cryptography systems are quantum key distribution (QKD) and post quantum cryptograph (PQC) systems; in this study, a network based on both QKD and PQC is proposed, along with a quantum key management system (QKMS) and a Q-controller to efficiently operate the network. The proposed quantum cryptography communication network uses QKD as its backbone, and replaces QKD with PQC at the user end to overcome the shortcomings of QKD. This paper presents the functional requirements of QKMS and Q-Controller, which can be utilized to perform efficient network resource management.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.42 no.6
• /
• pp.29-36
• /
• 2005

RFID(Radio Frequency Identification) will be used for recognizing things and offering distinctive information in Ubiquitous environment. But we are not ready to provide security service to RFID. Therefore we propose the approach of safe RFID system which provides the solution for eavesdrop, forgery, and modification based on Pre-Distribution protocol and RC5 security algorithm. First We distributes the secret key to the Tag with the Reader that is major subject on RFID system using Pre-Distribution protocol. Then we will provide to various security services and privacy protection using RC5 security algorithm. The proposed safe RFID system simulated on ATmega128 evaluate environment.