• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.4
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• pp.67-76
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• 2002

Kerberos is designed to provide strong authentication between client and application servers which are working in distributed network environment by using symmetric-key cryptography, and supposed to trust other systems of the realm. In this paper, we design an efficient and strong authentication mechanism by introducing the public/private-key to Kerberos. In the mechanism to make a system more secure, the value of the session key is changed everytime using MAC(message authentication code) algorithm with the long-term key for user-authentication and a random number exchanged through the public key. Also, we employ a mutual authentication method, which is used on challenge-response mechanism based on digital signatures, to improve trust between realms, and present a way of reducing the number of keys by simplifying authentication steps.

• Journal of Internet Computing and Services
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• v.7 no.3
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• pp.83-91
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• 2006

In this paper, we improved a cryptography system model based on the secure initial authentication public key with PKINIT of authentication and key recovery protocol. It is applied to all fields of cryptography system using certificate. This study presents two mechanisms to authenticate between member users. The first mechanism is initial authentication and distribution of session key by public key cryptography based on certificate between entity and server, and the second mechanism is a key recovery support protocol considering loss of session key in the secure communication between application servers.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1461-1464
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• 2005

In contrast with conventional networks, mobile ad hoc networks usually do not provide online access to trusted authorities or to centralized servers, and they exhibit frequent partitioning due to link and node failures and node mobility. For these reasons, traditional security solutions that require online trusted authorities or certificate repositories, but those are not well-suited for securing ad hoc networks. Moreover, a fundamental issue of securing mobile ad hoc networks is to ensure mobile nodes can authenticate each other. Because of its strength and efficiency, public key and digital signature is an ideal mechanism to construct the authentication service. Although this is already mature in the internet application, providing public key based authentication is still very challenging in mobile ad hoc networks. In this paper I propose a secure public key authentication service based on clustering model and trust model to protect nodes from getting false public keys of the others efficiently when there are malicious nodes in the network.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.3
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• pp.101-108
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• 2007

We follow the promising recent results of deploying the public key cryptography in sensor networks. Recent results have shown that the public key algorithms are computationally feasible on the typical sensor nodes. However, once the public key cryptography is brought to the sensor network, security services such like key authentication will be critically required. In this paper we investigate the public key authentication problem in the sensor network and provide several authentication protocols. Our protocols are mainly based on the non-solvable overhearing in the wireless environment and a distributed voting mechanism. To show the value of our protocols, we provide an extensive analysis of the used resources and the resulting security level. As well, we compare our work with other existing works. For further benefit of our protocols, we list several additional applications in the sensor network where our protocols provide a sufficient authentication under the constrained resources.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.3
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• pp.137-144
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• 2004

3GPP(3rd Generation Project Partnership)-WLAN(Wireless Local Area Network) interworking refers to the utilization of resources and access to services within the 3GPP system by the WLAN UE(User Equipment) and user respectively. The intent of 3GPP-WLAN Interworking is to extend 3GPP services and functionality to the WALN access environment. We propose an efficient mechanism for the setup of UE-initiated tunnels in 3GPP-WLAN interworking. The proposed mechanism is based on a secret key which is pre-distributed in the process of authentication and key agreement between UE and 3GPP AAA(Authentication, Authorization Accounting) server. Therefore it can avoid modular exponentiation and public key signature which need a large amount of computation in UE. Also the proposed scheme provides mutual authentication and session key establishment between UE and PDGW(Packet Data Gateway).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5C
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• pp.737-749
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• 2004

Kerberos authenticates clients using symmetric-key cryptography, and supposed to Oust other systems of the realm in distributed network environment. But, authentication and authorization are essential elements for the security. In this paper, we design an efficient and secure authentication/authorization mechanism by introducing the public/private-key and installing the proxy privilege server to Kerberos. In the proposed mechanism, to make a system more secure, the value of the session key is changed everytime using MAC(message authentication code) algorithm with the long-term key for user-authentication and a random number exchanged through the public key. Also, we reduce the number of keys by simplifying authentication steps. Proxy privilege server certifies privilege request of client and issues a privilege attribute certificate. Application server executes privilege request of client which is included a privilege attribute certificate. Also, a privilege attribute certificate is used in delegation. We design an efficient and secure authentication/authorization algorithm with Kerberos.

• The Transactions of the Korea Information Processing Society
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• v.5 no.8
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• pp.2083-2090
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• 1998

In this paper, we propose two authentication exchange schemes which combine public key-based mutual authentication with a Diffie-Hellman key derivation exchange. The security of key exchange of the proposed schemes depends on the discrete logarithm problem. The ,securtly of the etity authentication depends on that of the signature mechanism to be used in the proposed scheme. In comparisun with the Kerberos, X.509 exchanges, and ISO 3-way authentication protocol, the proposed schemes are not only simple and efficient. but also are resistant to the full range of replay and interceptiun attacks.

• Journal of the Korea Society of Computer and Information
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• v.11 no.3
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• pp.57-66
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• 2006

In this paper. proposes Multi_Kerberos certification mechanism that improve certification service of based on PKINIT that made public in IETF CAT Working Group. This paper proposed to a certificate other realm because search position of outside realm through DNS and apply X.509 directory certification system, to get public key from DNS server by chain (CertPath) between realms by certification and key exchange way that provide service between realms applying X.509, DS/DNS of based on PKINIT, in order to provide regional services. This paper proposed mechanism that support efficient certification service about cross realm including key management. the path generation and construction of Certificate using Validation Server, and recovery of Session Key. A Design of Multi_Kerberos system that have effects simplify of certification formality that reduce procedures on communication.

• Journal of KIISE:Information Networking
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• v.36 no.6
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• pp.545-551
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• 2009

In this paper, we propose the secure key management framework to connect USN with different network. Although connected USN with different network has no CA (Certificate Authority), it is important to use public key based cryptography system because this network consists of numerous devices. The proposed mechanisms focus on device authentication and public/private key management without existing PKI system of IP network. To solve no CA and certificate problems, the IDC (Identity Based Cryptography) concept is adopted in our proposed mechanism. To verify the possibility of realization, we make an effort to implement the proposed mechanisms to real system. In the test bed, both USN and PLC network are connected to IP network; and proposed mechanisms are implemented to PLC and sensor devices. Through this test using the proposed mechanism, we met the similar performance with symmetric algorithms on key generation and update process. Also, we confirmed possibility of connection between different network and device authentication.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.64-75
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• 2022

The method of accessing multiple control systems in the OT control network centered on operation technology uses the operator authentication technology of each control system. An example is ID/PW operator authentication technology. In this case, since the OT control network is composed of multiple control systems, operator authentication technology must be applied to each control system. Therefore, the operator must bear the inconvenience of having to manage authentication information for each control system he manages. To solve these problems, SSO technology is used in business-oriented IT networks. However, if this is introduced into the OT control network as it is, the characteristics of the limited size of the OT control network and rapid operator authentication are not reflected, so it cannot be seen as a realistic alternative. In this paper, a public key-based authentication mechanism was newly proposed as an operator authentication technology to solve this problem. In other words, an integrated public key certificate that applies equally to all control systems in the OT control network was issued and used to access all control systems, thereby simplifying the authentication information management and making access to the control system more efficient and secure.