• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.729-732
• /
• 2007

In this paper, we described about the home device authentication framework, certificate issuing process and home device authentication method. since the home device authentication scheme of the public key infrastructure would be more needed as the number of home device can participate in the home network increased, we described about the home device authentication system of the public key infrastructure. Moreover, we described about the construction method of CA adminstration interface for convenient CA administration.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.3
• /
• pp.507-513
• /
• 2007

In this paper, we propose an efficient authentication protocol based on certificateless signature scheme, which does not need anyinfrastructure to deal with certification of public keys, among the vehicles in Vehicular Ad-hoc Networks. Moreover, due to the characteristicsof VANET nodes (i.e., vehicles) that is fast and movement, the proposed protocol introduces the concept of interval signing key to overcome efficiently the problem of certificate revocation in traditional Public Key Infrastructure(PKI).

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

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.5 s.37
• /
• pp.161-170
• /
• 2005

The Certificate Revocation List(CRL) or the Online Certificate Status Protocol(OCSP)has been used to validate certificates. However, the CRL cannot validate certificates in realtime because of the Time-Gap problem and the OCSP server overloads in a large scale secure system. In addition, the client cannot access a wired LAN until the client has been authenticated by the authentication server on the IEEE 802. 1x framework. Therefore, the client cannot validate the authentication server's certificate using a certificate validation server. Thus, the client cannot authenticate the authentication server in realtime. To solve these problems this paper designed a secure system that can protect the content of communications and authenticate users in realtime on a wireless LAN The designed certificate validation protocol was proved that the stability and efficiency of the system was very high, the result of the validation had the presence, the speed of the validation was not affected by the system scale, the number of authorities user must trust was reduced to one, and the overload of the validation server was Protected. And the designed user authentication and key exchange protocols were Proved that the mutual authentication was possible in realtime and the fact of the authentication could be authorized by the CA because of using the authorized certificates.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2002.11a
• /
• pp.495-498
• /
• 2002

The need for network protection, accounting and resource management in foreign administrative domain requires appropriate security services. In this paper, we propose an access control protocol to support the authentication between mobile node and visiting subnet. Our hybrid way of approach aims to reduce computational overhead and minimize the use of network bandwidth. We also propose non-certificate based public-key cryptography to provide non-repudiation, which does not require CRL retrieval and certificate validation.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.9
• /
• pp.3322-3347
• /
• 2021

Cloud Storage is the primary component of many businesses on cloud. Majority of the enterprises today are adopting a multicloud strategy to keep away from vendor lock-in and to optimize cost. Auditing schemes are used to ascertain the integrity of cloud data. Of these schemes, only the Provable Data Possession schemes (PDP) are resilient to key-exposure. These PDP schemes are devised using Public Key Infrastructure (PKI-) based cryptography, Identity-based cryptography, etc. PKI-based systems suffer from certificate-related communication/computational complexities. The Identity-based schemes deal with the exposure of only the auditing secret key (audit key). But with the exposure of both the audit key and the secret key used to update the audit key, the auditing process itself becomes a complete failure. So, an Identity-based PDP scheme with Parallel Key-Insulation is proposed for multiple cloud storage. It reduces the risk of exposure of both the audit key and the secret key used to update the audit key. It preserves the data privacy from the Third Party Auditor, secure against malicious Cloud Service Providers and facilitates batch auditing. The resilience to key-exposure is proved using the CDH assumption. Compared to the existing Identity-based multicloud schemes, it is efficient in integrity verification.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.11
• /
• pp.1996-2001
• /
• 2006

Open System Authentication Method, Shared Key Method, Mac Based Authentication Method are very hard to use in wireless network that needs security. So now, many researches have been performed about 802.1x and user authentication method applying PKI. but certificate verification protocol has been used abolished list called CRL since it's first usage of PKI, there were still has a problem about distribution point. This paper applied CVS to use CA direct not to use CRL and OSCP server in order to improve this problems. Also It suggested the system that can make authentication steps more shorter using authentication server and Mutual authentication system by public certificate(small size/low speed wireless terminal can access to wireless network fast and safely)

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2006.06a
• /
• pp.176-180
• /
• 2006

In this paper, we propose an efficient authentication protocol based on certificateless signature scheme, which does not need any infrastructure to deal with certification of public keys, among the vehicles in Vehicular Ad-hoc Networks. Moreover, the proposed protocol introduces the concept of interval signature key for efficiently solving the problem of certificate revocation.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 1998.12a
• /
• pp.9-20
• /
• 1998

공개 키 암호 알고리듬은 사용자의 공개키가 그 사용자와 대응되는지 를 확인할 수 있는 방법이 필요하다. 이를 해결하기 위해 사용자들이 신뢰할 수 있는 인증기관에서 각 사용자의 공개키의 확인서를 발급한다. 그러나 비밀키의 노출, 사용자의 자격의 박탈 및 유효기간의 만료 등으로 인하여 확인서를 취소하여야 할 경우가 있다. 따라서 각 사용자는 상대방의 공개키가 유효한 것인지를 확인하여야 한다. 본 고에서는 지금까지 제시된 공개키 확인서의 취소 여부를 확인하는 방법들을 분석하고 효율적인 방법을 제시한다.

• Review of KIISC
• /
• v.8 no.3
• /
• pp.47-58
• /
• 1998

인증 서비스는 인터넷을 통한 전자상거래에서의 안전성 및 신뢰성을 확보하기 위해 반드시 필요한 요소이다. CPS 는 인증 서비스를 제공하는 CA에 의해 제공되는 인증 업무에 대해 세부적으로 기술한 문서로써, 인증서 사용자들이 인증기관의 신뢰도를 측정하는데 있어서 기준이 되는 역할을 한다. 본 고에서는 현재 인증 기술 부분의 연구에 있어서 주도적 역할을 하고 있는 IETF pkix 워킹 그룹의 Internet X.509 Public Key Infrastructure Certificate Policy and Cerification Practice Framework의 분석을 통해, CPS 의 역할 및 기능을 분석하였다.