• 한국컴퓨터정보학회논문지
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• 제28권7호
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• pp.67-75
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• 2023

본 논문에서는 Andola 등이 제안한 멀티서버 환경에서 동적 ID를 제공하는 사용자 인증 방식에 대한 안전성과 설계상의 문제점을 분석한다. 본 논문에서 Andola 등의 인증 방식을 분석한 결과, 스마트카드 분실 공격에 안전하지 않고, 이 공격으로 인하여 사용자의 패스워드 추측 공격이 가능하고, 결국 공격자는 세션키까지 생성할 수 있다. 본 논문에서는 이러한 문제를 해결하기 위해서 개선된 인증 방식을 제안하고, 이에 대한 안전성 분석한 결과 스마트카드 분실 공격, 패스워드 추측 공격, 사용자 가장 공격 등 여러 공격에 안전하였다. 또한 개선된 인증 방식은 안전한 동적 ID를 제공할 뿐만 아니라 해시함수의 계산 복잡도 측면에서도 효율적이다. 게다가 개선된 인증 방식은 전송량도 크게 증가하지 않아 전송비용의 측면에서도 효율적인 인증 방식이라고 할 수 있다.

• 한국산학기술학회논문지
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• 제12권10호
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• pp.4612-4617
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• 2011

Hsiang-Shih는 Yoon등의 스킴을 개선한 사용자 인증 스킴을 제안하였다. 그 후 An은 Hsiang-Shih이 제안한 스킴이 패스워드를 기반으로 하는 스마트카드를 이용한 사용자 인증 스킴에서 고려하는 보안 요구사항을 만족하지 못함을 보였다. 즉, Hsiang-Shih이 제안한 스킴에서 공격자가 사용자의 스마트카드를 훔치거나 일시적으로 접근하여 그 안에 저장된 정보를 추출하여 사용자의 패스워드를 알아낼 수 있음을 보였다. 그러나 An이 제안한 스킴도 패스워드 추측공격, 위조/위장 공격 등에 취약함을 보이고 개선된 사용자 인증 스킴을 제안하였다. 제안한 인증 스킴은 패스워드 추측공격이 불가능하고 사용자와 인증 서버가 상대방을 인증할 수 있는 효율적인 상호 인증방식을 제시하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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• pp.51-54
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• 2001

Recently Hwang and Li［1］ proposed a remote user authentication scheme using smart cards. Their scheme is based on the ElGamal public key cryptosystem and does not need to maintain a password table for verifying the legitimacy of the login users. In this paper, we proposed an advanced user authentication scheme using smart cards. Unlike Hwang and Li's scheme, smart card contains a pair of public parameters(h, P) where h is a hash function which is used in login phase. In result, we reduce one exponential computation frequency in login phase and two exponential computation frequencies in authentication phase with comparing the Hwang and Li's scheme. The proposed scheme not only provides the advantages as security of Hwang and Li's scheme, but also reduces computation cost.

• 한국멀티미디어학회논문지
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• 제20권3호
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• pp.500-510
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• 2017

Recently Lee et al. proposed an improved symmetric key-based remote user authentication scheme to eliminate the security weaknesses of Kumari et al.'s scheme. They hence claimed that their scheme is secure to various well-known attacks. However, we found that Lee et al.'s scheme is still insecure against outsider attack, smart card stolen and off-line password guessing attack. To overcome these security vulnerabilities, we propose an enhanced authentication scheme with key-agreement which is based on the fuzzy-extractor. Furthermore, we prove that the proposed scheme is more secure, and that it serves to gratify all of the required security properties. Finally, we compare the performance and functionality of the proposed scheme with those of previous schemes.

• International Journal of Contents
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• 제8권3호
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• pp.79-82
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• 2012

In digital contents distribution environments, a user authentication is an important security primitive to allow only authenticated user to use right services by checking the validity of membership. For example, in Internet Protocol Television (IPTV) environments, it is required to provide an access control according to the policy of content provider. Remote user authentication and key agreement scheme is used to validate the contents accessibility of a user. We propose a novel user authentication scheme using smart cards providing a secure access to multimedia contents service. Each user is authenticated using a subset of attributes which are issued in the registration phase without revealing individual's identity. Our scheme provides the anonymous authentication and the various permissions according to the combination of attributes which are assigned to each user. In spite of more functionality, the result of performance analysis shows that the computation and communication cost is very low. Using this scheme, the security of contents distribution environments in the client-server model can be significantly improved.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.154-156
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• 2012

This paper presents a user authentication scheme for healthcare application using wireless medical sensor networks, where wireless medical sensors are used for patients monitoring. These medical sensors' sense the patient body data and transmit it to the professionals (e.g., doctors, nurses, and surgeons). Since, the data of an individual are highly vulnerable; it must ensures that patients medical vital signs are secure, and are not exposed to an unauthorized person. In this regards, we have proposed a user1 authentication scheme for healthcare application using medical sensor networks. The proposed scheme includes: a novel two-factor professionals authentication (user authentication), where the healthcare professionals are authenticated before access the patient's body data; a secure session key is establish between the patient sensor node and the professional at the end of user authentication. Furthermore, the analysis shows that the proposed scheme is safeguard to various practical attacks and achieves efficiency at low computation cost.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권1호
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• pp.59-63
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• 2016

Secondary damage to the user is a problem in biometrics. A brain-wave has no shape and a malicious user may not cause secondary damage to a user. However, if user sends brain-wave signals to an authentication system using a network, a malicious user could easily capture the brain-wave signals. Then, the malicious user could access the authentication system using the captured brain-wave signals. In addition, the dataset containing the brain-wave signals is large and the transfer time is long. However, user authentication requires a real-time processing, and an encryption scheme on brain-wave signals is necessary. In this paper, we propose an efficient encryption scheme using a chaos map and adaptive junk data on the brain-wave signals for user authentication. As a result, the encrypted brain-wave signals are produced and the processing time for authentication is reasonable in real-time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권6호
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• pp.2005-2021
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• 2014

This paper proposes a novel image authentication scheme, aiming at tampering detection for block truncation coding (BTC) compressed image. The authentication code is generated by using the random number generator with a seed, and the size of the authentication code is based on the user's requirement, with each BTC-compressed image block being used to carry the authentication code using the data hiding method. In the proposed scheme, to obtain a high-quality embedded image, a reference table is used when the authentication code is embedded. The experimental results demonstrate that the proposed scheme achieves high-quality embedded images and guarantees the capability of tamper detection.

• 대한임베디드공학회논문지
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• 제5권3호
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• pp.168-174
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• 2010

User authentication is an important requirement to provide secure network service. Therefore, many authentication schemes have been proposed to provide secure authentication, such as key agreement and anonymity. However, authority of scheme is limited to one's self. It is inefficient when authenticated users grant a certification to other users who are in an organization which has a hierarchical structure, such as a company or school. In this paper, we propose the first authentication scheme to use Attributes-Based Re-encryption that creates a certification to other users with specified attributes. The scheme, which has expanded from Rhee et al. scheme, has optimized computation performance on a smart card, ensuring the user's anonymity and key agreement between users and server.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권1호
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• pp.395-413
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• 2016

Image authentication is a technique aiming at protecting the integrity of digital images. Reversible image authentication has attracted much attention of researcher because it allows to authenticate tampered regions in the image and to reconstruct the stego image to its original version losslessly. In this paper, we propose a new, reversible image authentication scheme based on adaptive prediction error expansion (PEE) technique. In the proposed scheme, each image block is classified into smooth or complex regions. Then, according to the characteristic of each block, the authentication code is embedded adaptively to achieve high performance of tamper detection. The experimental results demonstrated that the proposed scheme achieves good quality of stego images. In addition, the proposed scheme has ability to reconstruct the stego image to its original version, if no modification is performed on it. Also demonstrated in the experimental results, the proposed scheme provides higher accuracy of tamper detection than state-of-the-art schemes.