• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.6
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• pp.3299-3315
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• 2019

Deniable authentication (DA) is a protocol in which a receiver can generate an authenticator that is probabilistically indistinguishable from a sender. DA can be applied in many scenarios that require user privacy protection. To enhance the security of DA, in this paper, we construct a new deniable authenticated encryption (DAE) scheme that realizes deniable authentication and confidentiality in a logical single step. Compared with existing approaches, our approach provides proof of security and is efficient in terms of performance analysis. Our scheme is in an identity-based environment; thus, it avoids the public key certificate-based public key infrastructure (PKI). Moreover, we provide an example that shows that our protocol is applicable for e-voting systems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.298-299
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• 2019

In this paper, we propose a stable mutual authentication protocol between unmanned combat systems in tactical wireless networks where long distance communications are not always guaranteed due to a poor channel condition. The proposed protocol generates an authentication code using hash collision of arbitrarily selected random data. The authentication requester encrypts and transmits it to the authenticator. They performs authentication by sharing the valid authentication code. We analyze the safety of the proposed method for various attack scenarios.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.365-369
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• 2006

Multiple Message Authentication Codes can be represented by one of the Short MAC, Bloom Filter or Compressed Bloom Filler to reduce communication overheads. However, this will inevitably increase false positive rate (fpr) which is a false authentication probability of adversarial messages in trade-off of communication efficiency. While the simple short MAC scheme has the lowest fpr, one cannot choose arbitrary authenticator size. Bloom filter, randomized data structure often used for membership queries, can represent multiple MACs more flexibly with slightly higher fpr. Furthermore, compressed Bloom filter has the same fpr with the short MAC while maintaining its flexibility. Through our detailed analysis, we show that pros and cons of the three schemes are scenario specific. Therefore one can choose appropriate scheme under given parameters to achieve both communication efficiency and security based on our results.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.2
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• pp.55-69
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• 2010

This article proposed the authentication protocol for peer-to-peer resource sharing community. The proposed protocol does not require a priori information for generating and exchanging authentication key. Also this protocol can provide the delicate access control by allowing the user(authenticator) to assign the trust level to the authentication supplicant, which can be used to decide if the resource providing node will accept the resource sharing request from a resource requesting node. Trust Relationship Chaining provides the environment where trust levels (included in the trust table) of nodes in the resource sharing community are propagated among nodes when trust tables are exchanged between two nodes engaged in mutual authentication process and authentication refresh so that any two nodes which are not directly mutual-authenticated can assign the trust level each other for the access control for resource sharing. In the proposed protocol a node can implements the authentication refresh continuously to verify the effectiveness of authentication after mutual authentication so that the authentication of new node or authentication revocation(effectiveness cancellation) of the departed node can be propagated to the all the nodes in RSC and eventually safe resource sharing community is configured.

• Journal of Korea Society of Digital Industry and Information Management
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• v.16 no.4
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• pp.43-53
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• 2020

There are three standards for FIDO1 authentication technology: Universal Second Factor (U2F), Universal Authentication Framework (UAF), and Client to Authenticator Protocols (CTAP). FIDO2 refers to the WebAuthn standard established by W3C for the creation and use of a certificate in a web application that complements the existing CTAP. In Korea, the FIDO certified market is dominated by UAF, which deals with standards for smartphone (Android, iOS) apps owned by the majority of the people. As the market requires certification through FIDO on PCs, FIDO Alliance and W3C established standards that can be certified on the platform-independent Web and published 『Web Authentication: An API for Accessing Public Key Credentials Level 1』 on March 4, 2019. Most PC do not contain biometrics, so they are not being utilized contrary to expectations. In this paper, we intend to present a model that allows login in PC environment through biometric recognition of smartphone and FIDO UAF authentication. We propose a model in which a user requests login from a PC and performs FIDO authentication on a smartphone, and authentication is completed on the PC without any other user's additional gesture.

• Journal of the Korea Society of Computer and Information
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• v.17 no.7
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• pp.107-115
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• 2012

Recently, Li and Hwang scheme proposed a biometrics-based remote user authentication scheme using smart card. It is asserted that this scheme has very excellent benefits by the operation cost efficiency based on the smart card, one-way function and biometrics using random numbers. But this scheme cannot provide the properly authentication, especially, it is analyzed as the vulnerable security scheme for Denial-of-Service(DoS) attacks by impersonate attacks. The attacker controls the insecure channel, they can easily fabricate messages to pass the user's or server's authentication, and the malicious attacker can impersonate the user to cheat the server and can impersonate the server to cheat the user without knowing any secret information. This paper proposes the strong improved scheme which can respond to multiple attacks by supplementing the function of integrity check from the server which applied variable authenticator and OSPA without exposing the user's password information. It is supplemented pregnable of disguise attack and mutual authentication of Li and Hwang scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3747-3765
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• 2017

Existing authentication mechanisms in cellular mobile communication networks are realized in the upper layer by employing cryptographic techniques. Authentication data are broadcasted over the air in plaintext, enabling attackers to completely eavesdrop on the authentication and get some information about the shared secret key between legitimate nodes. Therefore, reusing the same secret key to authenticate several times results in the secret key's information leakage and high attacking rate. In this paper, we consider the most representative authentication mechanism, Authentication and Key Agreement (AKA), in cellular communication networks and propose an enhanced AKA scheme based on Physical Layer Authentication (AKA-PLA). Authentication responses generated by AKA are no longer transmitted in plaintext but masked by wireless channel characteristics, which are not available to adversaries, to generate physical layer authentication responses by a fault-tolerant hash method. The authenticator sets the threshold according to the authentication requirement and channel condition, further verifies the identity of the requester based on the matching result of the physical layer authentication responses. The performance analyses show that the proposed scheme can achieve lower false alarm rate and missing rate, which are a pair of contradictions, than traditional AKA. Besides, it is well compatible with AKA.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.5
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• pp.1132-1139
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• 2008

The structure of medical profession is composed of multiple relations among state, patients, and medical professions. There are conflicts between the nation and medical professions because the nation controls the monopoly of medical professions through medical policies. Patients make relations with medical profession as medical consumers. And medical professions compete each other in order to gain the control of the medical market. This paper attempts to review the dynamic relations between the nation and medical professions. The medical professions and the nation are in conflict about the control of the autonomy of medical professions. The medical professions want to exercise the monopoly rights in their own area and, on the other had, the nation wants to prevent problems that might result from the monopoly by regulations and to have the control over the national operation. Given this, the common view of medical sociology is that the nation and the medical professions are in constant conflict. The arguments that the present medical sociology has on the relationship between the nation and medical professions can be summarized like these: first, the nation is the authenticator of medical system; second, the nation is a medical provider and consumer; and, third, the nation is a mediator of regulations and conflicts. Based on the above mentioned relations between the nation and medical professions, this paper attempts to see how the nation, which is one component of the medical structure, make influences on Korean Oriental doctors and Traditional Chinese doctors. So as to do this, the changes in medical policies and promoting policies for Korean Oriental medicine and Traditional Chinese medicine are analyzed. Finally, the differences in national policies of Korean Oriental medicine and Traditional Chinese medicine are compared.