• Journal of Korea Spatial Information System Society
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• v.7 no.3 s.15
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• pp.13-24
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• 2005

This paper proposes a model for the location information grading policy. Location information grading policy is that government would give a public notice of criterion for location information quality, and location information operators should elucidate the grade of provided location information. As the quality grade of services is provided in the 'terms of use' with the detailed quality specification and quality range, the user can understand the quality of location information, and can select more suitable service for their purposes. Additionally, the qualiy grading policy can enforce the location information operators and location service providers to support more stable and reliable service quality. In this paper, we propose the model of location information grades, the typical classification of quality, and the realitic policy applying model. Recent enacted 'Location Information Law' are expected to activate korean information market. In this situation, proposed location information grading policy take a role in protecting location privacy and improving the reliability of location information services.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.669-685
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• 2003

Nowadays mobile phones and PDAs are part and parcel of our lives. By carrying a portable mobile device with us all the time we are already living in partial Pervasive Computing Environment (PCE) that is waiting to be exploited very soon. One of the advantages of pervasive computing is that it strongly supports the deployment of Location-Based Service(s) (LBSs). In PCE, there would be many competitive service providers (SPs) trying to sell different or similar LBSs to users. In order to reserve a particular service, it becomes very difficult for a low-computing and resource-poor mobile device to handle many such SPs at a time, and to identify and securely communicate with only genuine ones. Our paper establishes a convincing trust model through which secure job delegation is accomplished. Secure Job delegation and cost effective cryptographic techniques largely help in reducing the burden on the mobile device to securely communicate with trusted SPs. Our protocol also provides users privacy protection, replay protection, entity authentication, and message authentication, integrity, and confidentiality. This paper explains our protocol by suggesting one of the LBSs namely“Secure Automated Taxi Calling Service”.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1171-1177
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• 2010

Recently RFID system is used in various fields such as distribution industry, medical industry and military service. The technology for protecting individual privacy is necessary to adapt RFID system in several applications. This paper proposes an authentication protocol which conducts mutual authentication between back-end database and tag using hash function. The proposed protocol satisfies various RFID security requirements : mutual authentication, anonymity, confidentiality, integrity, replay attack, location trace. This protocol reduces the time for authentication minimizing the number of hash operation in back-end database.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.125-134
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• 2008

A great number of RFID authentication protocols have been proposed for the secure RFID system. These are typically divided into three types according to primitive that they use : Hash-based, Re-encryption based, and XORing-based protocol. The well-known attacks in RFID system are eavesdropping. impersonating, location tracking, and so on. However, existing protocols could not provide security against above attacks, or it was not efficient to search for tags on database. Therefore, in this paper we present a protocol which is secure against above attacks by using hash function and makes Database search tags easily by attaining the state information of previous session through the shared values with all tags and database.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6C
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• pp.593-600
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• 2005

Recently, RFID system is a main technology to realize ubiquitous computing environments. Because RFID system that is an automatic identification technology using radio frequency is a system to read and write the data of the entity. Therefore, many companies are interested in RFID system to reduce supply chain management and inventory control cost. However, for providing secure service, RFID authentication technology secure against tracking by an adversary is researched first. In this paper, we proposed security level based RFID authentication protocol providing reduce computational and communicational workload in the back-end database. The proposed protocol is secure against reply attack, spoofing attack, traffic analysis, and location privacy, since the proposed protocol based on the security of the hash function.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.778-783
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• 2006

최근 센서 네트워크 분야를 비롯해 네트워크 분야에서 내용 보호, 인증뿐만 아니라 Source의 위치 프라이비시와 관련하여 많은 연구가 이루어지고 있다. 특히 센서 네트워크에서의 Source 위치는 실제 센서의 지리적 위치이기 때문에 Source의 위치를 노출하지 않는 것이 매우 중요하다. 그리고 인터넷과 Ad-Hoc 네트워크에서 익명성(Anonymity)을 제공하기 위한 기법들이 많이 제안되었지만, 이러한 기법들은 센서 네트워크에 적합하지 않기 때문에 센서 네트워크의 특성에 맞는 익명성 제공 요법이 요구되고 있다. 본 논문에서는 Source의 익명성과 관련해 센서네트워크에서 나타날 수 있는 Eavesdropper의 유형을 정의하고, 이러한 Eavesdropper의 유형에 따라 Source의 익명성을 제공할 수 있는 방법을 제안하였다. 그리고 제안한 방법이 얼마만큼의 익명성을 제공하는가를 정량화하기 위해 엔트로피(Entropy) 성질을 이용해 수학적으로 분석하였다. 그 결과, 제안하는 방법이 보다 높은 익명성을 제공하고, 센서의 전송 거리가 Source의 익명성 제공에 있어 매우 중요한 요소임을 확인하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.100-102
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• 2005

유비쿼터스는 현재의 제한된 컴퓨팅 환경을 떠나서 시간과 장소에 구애받지 않는 자유로운 컴퓨팅 환경을 제공함으로서 각광받고 있다. 그 중 언제어디서나 정보를 주고받을 수 있으며 가격과 성능 면에서 단연 뛰어난 RFID(Radio Frequency Identification)의 중요성은 점점 증가되고 있는 추세이다. 그러나, 이와 같은 우수성에도 불구하고, 정보 유출의 위험성을 내포하고 있으며, 개인의 위치 추적이나, 비 접근 권한자의 위장행세 등의 사용자 프라이버시 보호에 대한 많은 문제점들을 수반한다. 현재까지 이와 관련된 연구들이 활발히 진행되고 있다. 특히 그 중, Ohkubo의 해시함수를 이용한 프로토콜은 프라이버시 보호 측면에서 위치추적 공격(location tracking), 전방위보안성(forward security)과 같은 문제들에 대한 해결책을 제시하고 있으나, 해시함수를 태그에 직접 구현하는 것은 현재까지는 불가능한 상태이다. 또한, Martin Feldhofer는 대칭키 암호 알고리즘인 AES(Advanced Encryption Standard)를 태그에 구현을 함으로서 암호학적인 강도를 높였으나, 위치추적 공격에 대한 문제정과 물리적 공격에 대한 가정을 하지 않은 단점을 가지고 있다. 본 논문에서는 기존연구에서의 문제점들을 보완하고자 현실적으로 구현 가능한 AES를 사용하고, 위치추적 공격, 비권한자 접근(unauthorized access) 공격과 물리적 공격으로부터 안전하며 전방위보안성을 제공하는 기법을 제안한다.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.11
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• pp.495-502
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• 2013

In this paper, we present an anonymous authentication and location assurance protocol for secure location-aware services over vehicular ad hoc networks (VANETs). In other to achieve our goal, we propose the notion of a location-aware signing key so as to strongly bind geographic location information to cryptographic function while providing conditional privacy preservation which is a desirable property for secure vehicular communications. Furthermore, the proposed protocol provides an efficient procedure based on hash chain technique for revocation checking to effectively alleviate communication and computational costs on vehicles in VANETs. Finally, we demonstrate comprehensive analysis to confirm the fulfillment of the security objectives, and the efficiency and effectiveness of the proposed protocol.

• Journal of Korea Multimedia Society
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• v.13 no.5
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• pp.710-721
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• 2010

Recently, for the advancement of embedded technology about mobile device, a new kind of service, mash-up is appeared. It is service or application combining multimedia content making tool or device and web-GIS(geographic information system) service in the mobile environment. This service can be ease to use for casual user and can apply in various ways. So, It is served in web 2.0 environment actively. But, in the mashup service, because generated multimedia contents linked with web map are new type of multimedia contents which include user's migration routes in the space such as GPS coordinates. Thus, there are no protection ways for intellectual property created by GIS web-map service users and user's privacy. In this paper, we proposed a location and user information hiding scheme for GIS web-map service. This scheme embeds location and user information into a picture that is taken by camera module on the mobile phone. It is not only protecting way for user's privacy but is also tracing way against illegal photographer who is peeping person through hidden camera. And than, we also realized proposed scheme on the mobile smart phone. For minimizing margin of error about location coordinate value against contents manipulating attacks, GPS information is embedded into chrominance signal of contents considering weight of each digit about binary type of GPS coordinate value. And for tracing illegal photographer, user information such as serial number of mobile phone, phone number and photographing date is embedded into frequency spectrum of contents luminance signal. In the experimental results, we confirmed that the error of extracted information against various image processing attacks is within reliable tolerance. And after file format translation attack, we extracted embedded information from the attacked contents without no damage. Using similarity between extracted one and original templete, we also extracted whole information from damaged chrominance signal of contents by various image processing attacks.