• Journal of Communications and Networks
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• v.14 no.1
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• pp.10-14
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• 2012

When tag privacy is required in radio frequency identification (ID) system, a reader needs to identify, and optionally authenticate, a multitude of tags without revealing their IDs. One approach for identification with lightweight tags is that each tag performs pseudo-random function with his unique embedded key. In this case, a reader (or a back-end server) needs to perform a brute-force search for each tag-reader interaction, whose cost gets larger when the number of tags increases. In this paper, we suggest a simple and efficient identification technique that reduces readers computation to $O$(${\sqrt{N}}$ log$N$) without increasing communication cost. Our technique is based on the well-known "meet-in-the-middle" strategy used in the past to attack symmetric ciphers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.491-494
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• 2005

In this paper, a QT_rev protocol is proposed for identifying all the tags within the identification range. The proposed QT_rev protocol revises the QT protocol, which has a memoryless property. In the QT_rev protocol, the tag will send the remaining bits of their identification codes when the query string matches the first bits of their identification codes. After the reader receives all the responses of the tags, it knows which bit is collided. If the collision occurs in the last bit, the reader can identify two tags simultaneously without further query.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.526-529
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• 2006

In this paper, a QT_ss protocol is proposed for identifying all the tags within the identification range. The proposed QT_ss protocol revises the QT protocol. which has a memoryless property. In the QT_ss protocol, the tag will send all the bits of their identification codes when the query string matches the first bits of their identification codes. While the tags are sending their identification codes. if the reader detects a collision bit, it will send a signal to the tags to stop sending. According to the simulation results, the QT_ss protocol outperforms the QT protocol in terns of the number of response bits.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.4
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• pp.976-982
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• 2010

Agricultural products are one of the major food, But in recent years, It's not easy for Consumers to buy them. Cause there are not sure about the quality of the cheap foreign agricultural product imported. There are not even sure where they have been produced, Some excessive use of domestic pesticides, And Environmental pollution caused by soil contamination of plantation, It's not only matter with the conscience of the Sellers and producers. The government recommends agricultural producers to attach the mark to identify where the products are made originally. However, if producers do not comply with the recommendation, it become useless. Recently, because of the increased interest to health and food, Consumers want accurate and reliable information about The agricultural products, They buy. In this paper, Based on the RFID technology, RFID tags attached to agricultural products when consumers buy, Through the RFID reader to read RFID tags, Which make Easy to accurately convey Production of agricultural information and safety information to consumers. These features have been implemented with the traceability system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.5
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• pp.59-71
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• 2005

A RFID (Radio Frequency Identification) system receives attention as the technology which can realize the ubiquitous computing environment. However, the feature of the RFID tags may bring about new threats to the security and privacy of individuals. Recently, Juels proposed the minimalist cryptography for very low-cost RFID tags, which is secure. but only under the impractical assumption such that an adversary is allowed to eavesdrop only the pre-defined number of sessions. In this paper, we propose a scheme to protect privacy for very low-cost RFID systems. The proposed protocol uses only bit-wise operations without my costly cryptographic function such as hashing, encryption which is secure which is secure against an adversary who is allowed to eavesdrop transmitted message in every session any impractical assumption. The proposed scheme also is more efficient since our scheme requires less datas as well as few number of computations than Juels's scheme.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.5
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• pp.71-82
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• 2011

The RFID system provides undeniable advantages so that it is used for various application. However recent RFID system is vulnerable to some attacks as eavesdropping, replay attack, message hijacking, and tag tampering, because the messages are transmitted through the wireless channel and the tags are cheap. Above attacks cause the tag and reader impersonation, denial of service by invalidating tag, and the location tracking concerning bearer of tags, A lot of RFID authentication protocol bas been proposed to solve the vulnerability. Since Weis, Sanna, Rivest, and Engel, proposed the bash-based RFID authentication protocol, many researchers have improved hash-based authentication protocol and recent bash-based authentication protocols provide security and desirable privacy. However, it remains open problem to reduce the tag identification time as long as privacy and security are still guaranteed. Here we propose a new protocol in which the tags generate the message depending on the state of previous communitions between tag and reader. In consequence, our protocol allows a server to identify a tag in a reasonable amount of time while ensuring security and privacy, To be specific, we reduced the time for the server to identify a tag when the last session finished abnormally by at least 50% compared with other bash-based schemes that ensure levels of security and privacy similar to ours.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.313-319
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• 2009

Recently the RFID system, which can recognize multiple tags simultaneously through wireless communication, is emerging as a new technology that can replace the barcode system. Furthermore, related industries are carrying out active research on tags and authentication protocols with guaranteed security that are widely applicable to logistics, distribution, etc. The present study proposes a protocol with enhanced security by introducing the concept of RBAC to the authentication protocol, and a method with lower security for effective mass authentication. The proposed method is advantageous in that it guarantees security against spoofing attack, traffic analysis, replay attack, etc. based on hash function.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.12
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• pp.1294-1301
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• 2008

Under passive RFID environment, this paper presents a new localization of a mobile robot traversing over the floor covered with tags, which is superior to existing methods in terms of estimation performance and cost effectiveness. Basically, it is assumed that a mobile robot is traveling along a series of straight line segments, each segment at a certain constant velocity, and that the number of tags sensed by a mobile robot at each sampling instant is at most one. First, for a given line segment with known starting point, the velocity and position of a mobile robot is estimated using the spatial and temporal information acquired from the traversed tag. Some discussions are made on the validity of the basic assumptions and the localization for the initial segment with unknown starting point. Second, for a given tag distribution density, the optimal tag arrangement is considered to reduce the position estimation error as well as to make easy the tag attachment on the floor. After reviewing typical tag arrangements, the pseudorandom tag arrangement is devised inspired from the Sudoku puzzle, a number placement puzzle. Third, through experiments using our passive RFID localization system, the validity and performance of the mobile robot localization proposed in this paper is demonstrated.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.1
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• pp.19-25
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• 2012

In evaluating the performance of RFID systems, the tag anti-collision arbitration has been considered to be an important issue. For BT(Binary Tree) and ABS( Adaptive Binary Splitting) protocols, the so-called capture effect, which presumably happens frequently in the process of readers' receiving messages from multiple tags, can lead to some failures in detecting all tags in BT and ABS. In this paper, we propose a new anti-collision protocol, namely FTB (Feedback TagID with Binary splitting), which can solve the aforementioned problem and improve the performance.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.2
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• pp.235-242
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• 2012

In RFID System, one of the problem that we must slove is to devise a good anti-collision algorithms to improve the efficiency of tag identification which is usually low because of tag collision. Among of the existing RFID anti-collision algorithm, BS (Binary Search) algorithm, though simple, has a disadvantage that the stage of times used to identify the tags increase exponentially as the number of tags does. In this paper, I propose a new anti-collision algorithm called Multi-collision reflected frame which restricts the number of stages and decided bit. Since the proposal algorithm keep the length size of UID and density of total tag when have 100%. The simulation results showed that the proposed algorithm improves the efficiency by 30~50% compared to the existing algorithm.