• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.6
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• pp.83-92
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• 2009

Ari Juels proposed Yoking-Proof protocol for authenticating multiple tags simultaneously using RFID system. Because common Yoking-Proof methods authenticate by using MAC (Message Authentication Code), it is difficult to apply them to inexpensive tags. It is also difficult to implement common hash functions such as MD5 in inexpensive tags. So, Ari Juels also proposed a lightweighted Yoking-Proof method with only 1 authentication. However, Minimalist MAC, which is a lightweighted MAC used in the proposed method is for single-use, and the proposed structure is vulnerable to replay attacks. Therefore, in this study, the minimalist MAC using Lamport's digital signature scheme was adopted, and a new type of Yoking-Proof protocol was proposed where it uses tags that are safe from replay attacks while being able to save multiple key values.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11B
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• pp.1272-1282
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• 2009

This paper consists of two parts: the protocol for tag-to-tag mesh network and the implementation of dual-radio RFID system. Recently, RFID has been adopted in ports or warehouse, being attached to containers and palettes for loading/unloading automation. However, the RFID system has encountered one problem - some tags cannot receive any command from reader intermittently due to signal interference by containers or field equipments (e. g. cranes and yard tractors). This area where reader signal cannot reach is called dead-zone. The proposed method for solving the dead-zone problem is as follows. A zone which can be communicated directly between readers and tags communicates in 433MHz frequency band in compliance with ISO/IEC 18000-7 standard. On the other hand, dead-zone communicates in 2.4GHz frequency band by using tag-to-tag mesh network in compliance with IEEE 802.15.4 standard. The proposed method can not only save much cost to install additional readers but also help resolve the dead-zone problem. Furthermore, it can provide the easier, faster, and more economical network infrastructure.

• Journal of the Korea Society of Computer and Information
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• v.15 no.8
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• pp.107-115
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• 2010

RFID (Radio Frequency IDentification) technology, automatic identification and data capture technologies in ubiquitous computing is an essential skill. Low-cost Radio Frequency Identification tags using memory and no physical contact due to the ease of use and maintenance of excellence are going to use expanded. However, it is possible to the illegal acquisition of the information between RFID tags and readers because RFID uses the RF signal, and the obtained information can be used for the purpose of location tracking and invasion of privacy. In this paper, we proposed the security scheme to protect against the illegal user location tracking and invasion of privacy. The security scheme proposed in this paper, using Gray Code and reduced the capacity of the calculation of the actual tags, However, it is impossible for the malicious attacker to track information because tag information transmitted from the reader is not fixed. Therefore, even if the tags information is obtained by a malicious way, our scheme provides more simple and safe user privacy than any other protection methods to protect user privacy, because not actual information but encrypted information is becoming exposed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3A
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• pp.360-367
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• 2006

In this paper, we designed a digital codec of an RFID tag for EPC global generation 2 class 1. There are a large number of studies on RRD standard and anti-collision algorithm but few studies on the design of digital parts of the RFID tag itself. For this reason, we studied and designed the digital codec hardware for EPC global generation 2 class 1 tag. The purpose of this paper is not to improve former studies but to present the hardware architecture, an estimation of hardware size and power consumption of digital part of the RFID tag. Results are synthesized using Synopsys with a 0.35um standard cell library. The hardware size is estimated to be 111640 equivalent inverters and dynamic power is estimated to be 10.4uW. It can be improved through full-custom design, but we designed using a standard cell library because it is faster and more efficient in the verification and the estimation of the design.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.729-734
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• 2011

In this paper, e-Meters middleware and applications using standardized middleware in the EPCglobal is suggested. An standardized middleware of the EPCglobal is designed to manage as a form of SCM and other logistics. In order to support a variety of services using RFID-based, the system must be able to support each protocol. The main features of e-Meters middleware is consist of information status and delivery, distributed database processing, event data analysis, and handling. To operate real time e-Meters system information, The realized middleware is configured to process the results of data collection.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3A
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• pp.184-194
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• 2005

One of the most important factors that decide the overall performance of RFID system is anti-collision algorithm. By enhancing the anti-collision algorithm, we can increase the number of RFID tags that can be processed in unit time. Two anti-collision algorithms are most widely prevailed: one is ALOHA-based protocol and the other is a binary tree walking method, but these are still under research. In this paper, we suggest an anti-collision algorithm named AAC(Address Allocating and Calling) using pre-distributed random address, which is much faster and more efficient than existing ones. Finally, we evaluate our scheme using mathematical analysis and computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8B
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• pp.805-811
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• 2009

Firstly, this dissertation suggests the tag ID transfer method using two-dimensional arrangement. Secondly, provide better and stable security system compare to existing one by transferring tag; ID using established two-dimensional arrangement. Thirdly, provide operating module, which possible to descramble two-dimensional arrangement, with a character set when descrambling in a tag and a server. Lastly, suggest safe key transfer using a character set and two-dimensional arrangement. In order to embody suggested system and assess, transferred two-dimensional arrangement several times to carry out the experiment. Confirmed that it is impossible for suggested system to decode key patterns compare to existing RFID systems.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1421-1424
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• 2009

RFID(Radio-Frequency IDentification) 시스템은 무선주파수를 이용한 자동 인식 기술로 개인의 위치 추적이나 사용자 프라이버시와 같은 정보 유출의 위험성을 내포하고 있다. 이러한 문제점을 해결하기 위해 대칭키 기반의 AES 암호화 알고리즘은 해시함수나 공개키 암호화 기법에 비해 메모리를 적게 소모하고 구현이 쉬운 장점 때문에 수동형 RFID태그에 더 적합하다. 그러나 기존의 AES를 이용한 RFID 인증 프로토콜에서는 항상 고정된 키를 이용하여 암호화하였고 태그와 리더사이의 안전하지 않은 무선 채널에서 공격자에 의해 키 값이 노출될 수 있는 또 다른 문제점을 가지고 있다. 본 논문에서는 태그와 서버의 고정된 키와, 리더 태그 서버에서 생성된 난수를 차례로 이용하여 대칭키를 변환한다. 그리고 매 세션마다 변환된 키로 난수를 암호화 하면서 태그와 리더를 상호 인증한다. 이와 같이 변환된 키를 이용할 경우 키 값의 노출 문제가 해결되며, 이 키를 통해 암호화하여 인증할 경우 재전송, 도청, 위치추적 및 스푸핑과 같은 공격에도 안전하다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1C
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• pp.54-62
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• 2012

A Wi-Fi mesh network providing multi-hop wireless connections based on IEEE 802.11 PHY/MAC technology has recently received a significant attention as a network infrastructure that interconnects RFID systems and wireless sensor networks (WSNs). However, the current IEEE 802.11 contention-based MAC protocol cannot fully utilize the network capacity due to eithor frame collisions or unused network resources. In this paper, we propose a novel multi-channel scheduling MAC (MCS-MAC) protocol for Wi-Fi mesh networks. Under the secondary interference model of Wi-Fi mesh networks, the MCS-MAC protocol can maximize the network throughput via activation of collision-free links that has a maximal link weight. Through the simulations, we show that the throughput of the MCS-MAC protocol is at least three times higher than that of existing MAC protocols in Wi-Fi mesh networks.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.1
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• pp.31-46
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• 2012

The most critical technology to implement ubiquitous health care is Ubiquitous Sensor Network (USN) technology which makes use of various sensor technologies, processor integration technology, and wireless network technology-Radio Frequency Identification (RFID) and Wireless Sensor Network (WSN)-to easily gather and monitor actual physical environment information from a remote site. With the feature, the USN technology can make the information technology of the existing virtual space expanded to actual environments. However, although the RFID and the WSN have technical similarities and mutual effects, they have been recognized to be studied separately, and sufficient studies have not been conducted on the technical integration of the RFID and the WSN. Therefore, EPCglobal which realized the issue proposed the EPC Sensor Network to efficiently integrate and interoperate the RFID and WSN technologies based on the international standard EPCglobal network. The proposed EPC Sensor Network technology uses the Complex Event Processing method in the middleware to integrate data occurring through the RFID and the WSN in a single environment and to interoperate the events based on the EPCglobal network. However, as the EPC Sensor Network technology continuously performs its operation even in the case that the minimum conditions are not to be met to find complex events in the middleware, its operation cost rises. Moreover, since the technology is based on the EPCglobal network, it can neither perform its operation only for the sake of sensor data, nor connect or interoperate with each information system in which the most important information in the ubiquitous computing environment is saved. Therefore, to address the problems of the existing system, we proposed the design and implementation of USN integration management system. For this, we first proposed an integration system that manages RFID and WSN data based on Session Initiation Protocol (SIP). Secondly, we defined the minimum conditions of the complex events to detect unnecessary complex events in the middleware, and proposed an algorithm that can extract complex events only when the minimum conditions are to be met. To evaluate the performance of the proposed methods we implemented SIP-based integration management system.