• Journal of Korea Society of Industrial Information Systems
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• v.15 no.4
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• pp.1-5
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• 2010

To operate safely VANET applications, authenticaton is necessary to identify val d participants and prevent malicious parties from modifying messages. This paper proposes an efficient authentication protocol for the vehicle registration in VANET environment. The topology of VANET changes rapidly due to high-speed movement of vehicles, thus it is need to reduce the computational burden of the authentication protocol. Therefore, this protocol uses only one-way hash functions and EOR operations to register vehicles.

• Annual Conference of KIPS
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• 2009.04a
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• pp.1436-1437
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• 2009

RFID 시스템에서 리더와 태그간의 통신은 안전하지 않은 채널을 통하여 수행된다. 최근 Lee등은 해쉬 함수와 동기화된 비밀 정보를 이용한 RFID 상호 인증 프로토콜인 LAK 프로토콜을 제안하였다. 하지만 Cao-Shen은 LAK 프로토콜이 재전송 공격에 취약하며, 공격자가 합법적인 태그로 위장할 수 있음을 증명하였다. 본 논문에서는 안전한 일방향 해쉬 함수를 기반의 새로운 2-패스 RFID 상호 인증 프로토콜인 TRMA 프로토콜을 제안한다. 제안한 TRMA 프로토콜은 RFID 태그와 리더 간에 2라운드만을 수행하여 상호 인증을 수행할 수 있으며, 여러가지 공격들에 안전하며 통신 효율성을 보장한다.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3128-3137
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• 2000

Secret sharing scheme is a cryptographic protocol in which a dealer distribures shares of a secret among a set of participants such that only authorized set of participants can recover the secret at a later. Secret sharing is an important cryptographic primitive in management of secret information, secure multiparty protocol and group-oriented cryptography, etc. In this paper, we propose an efficient, on-line secret sharing scheme based on one-way hash function. This scheme provides the property to share multiple secrets and allows participants to be added/deleted dynamically, without having to redistributo new shares. Proposed scheme has advantage to detect cheating and identify of all cheater, regardless of then number. Frthermore, it is more eficient than previous schemes.

• Annual Conference of KIPS
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• 2004.11a
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• pp.557-560
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• 2004

원격 사용자가 시스템에 로그인 할 경우에 그 로그인 사용자를 인증하기 위한 많은 방안들이 제안되고 있다. 본 논문에서는 스마트 카드를 이용한 향상된 사용자 인증 방법을 제안한다. 제안된 기법의 안전성은 이산대수 문제의 어려움과 일방향 해쉬 함수의 특성에 기반하고 있으며, 재전송 공격과 위장 공격에 취약점을 드러내지 않는다.

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.309-316
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• 2005

Recently, RFID system is a main technology to realize ubiquitous computing environments, but the feature of the RFID system may bring about various privacy problem. So, many kinds of protocols To resolve this problem are researched. In this paper, we analyse the privacy problem of the previous methods and propose more secure and effective authentication protocol to protect user's privacy. Then we prove that the proposed protocol is secure and effective as we compare the proposed protocol with previous methods. The proposed protocol is based on Challenge-Response using one-way hash function and random number. The proposed protocol is secure against replay attack, spoofing attack and so on. In addition, the proposed protocol is proper for distributed database environment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.1
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• pp.101-111
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• 2004

Preneel, Govaerts, and Vandewalle considered the 64 basic ways to construct a collision resistant hash function from a block cipher. They regarded 12 of these 64 schemes as secure, though no proofs or formal claims were given. Black, Rogaway, and Shrimpton presented a more proof-centric look at the schemes from PGV. They proved that, in the black box model of block cipher, 12 of 64 compression functions are CRHFs and 20 of 64 extended hash functions are CRHFs. In this paper, we present 64 schemes of block-cipher-based universal one way hash functions using the main idea of PGV and analyze these schemes in the black box model. We will show that 30 of 64 compression function families UOWHF and 42 of 64 extended hash function families are UOWHF. One of the important results is that, in this black box model, we don't need the mask keys for the security of UOWHF in contrast with the results in general security model of UOWHF. Our results also support the assertion that building an efficient and secure UOWHF is easier than building an efficient and secure CRHF.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.5
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• pp.71-78
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• 2009

In RFID system, the communicated data can be easily eavesdropped and tampered with by an attacker because the communication between the reader and the tag is performed in an insecure channel. Therefore, authentication is an important role in RFID applications for providing security and privacy. In 2006, Lee, Asano and Kim proposed an RFID mutual authentication protocol (the LAK protocol) which utilizes a hash function and synchronized secret information. However, Cao and Shen showed that the LAK protocol is vulnerable to replay attack, and therefore an adversary can impersonate the tag. This paper proposes a new simple two-round RFID mutual authentication (TRMA) protocol based on secure one-way hash function. As a result, the proposed TRMA protocol not only can prevent various attacks and but also provides communication efficiency since they mutually authenticate by performing two-round between RFID tag and RFID reader.

• Journal of KIISE:Information Networking
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• v.28 no.3
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• pp.309-320
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• 2001

This paper deals with security issues in a mobile agent system, especially protecting agent data from malicious agent servers. For this purpose, one-time key generation system, OKGS in short, is proposed. In OKGS, we integrate notions of a one-way hash function and a coupler. One-way function plays a major role in ensuring confidentiality and integrity of agent data. And the notion of a coupler is used to establish inter-relationship among consecutive encryption keys for agent data, i.e. all agent keys form a unidirectional chain. With these two features of OKGS, therefore, only the agent owner, who creates the agent bearing data, can decrypt and protect all the agent data which are gathered in the itinerary.

• Annual Conference of KIPS
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• 2003.11c
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• pp.1783-1786
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• 2003

최근에 YEH-SHEN은 스마트 카드를 이용한 일회용 패스워드 인증 스킴을 제안했다. 본 논문에서는 YEH-SHEN의 인증 스킴이, 사용자 등록 단계에서 로그인 사용 횟수를 N번으로 제한하고 있으며 또한 로그인 단계서 일회용 패스워드를 계산할 때 일방향 해쉬 함수를 (N-로그인 횟수)번 만큼 반복 수행해야 한다는 문제점을 지적한다. 또한 본 논문에서는 이를 개선한 보다 효율적인 새로운 인증 스킴을 제안하고 제안된 스킴이 여러 보안 요구사항에 안전함을 보인다.

• Annual Conference of KIPS
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• 2009.04a
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• pp.1459-1462
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• 2009

최근 Yang과 An은 기존의 RFID 인증 메커니즘들이 가지고 있는 프라이버시 침해 문제를 분석하고 보다 안전하고 효율적인 사용자의 프라이버시를 보호할 수 있는 RFID(YA-RFID) 인증 프로토콜을 제안하였다. 그들은 제안한 YA-RFID 인증 프로토콜이 공격자의 재전송 공격, 스푸핑 공격, 그리고 위치 트래킹 공격에 대해 안전하다고 주장하였다. 하지만 본 논문에서는 그들의 주장과는 달리 YA-RFID 프로토콜이 여전히 위치 트래킹 공격에 취약함을 증명하며, 더 나아가 동일한 연산 효율성을 보장하며 위치 트래킹 공격을 막을 수 있는 간단히 개선된 일회성 난수와 안전한 일방향 해쉬 함수 기반의 RFID 인증 프로토콜을 제안한다.