• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.35-44
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• 2006

As the E-commerce and E-business are developed actively, using certificate is incremented rapidly. The certificate validation must be confirmed at first in E-commerce and the OCSP Responder can offer CSI to the client using OCSP. With the rapid development of the E-commerce based on the Internet, a lot of clients request CSI to OCSP Responder. So, the load to OCSP Responder is increased and the OCSP Responder may be overloaded. Therefore, for distributing the load to an OCSP Responder, D-OCSP is introduced. As the CRL has a lot of information about revoked certificates and have a high exposure Possibility of information in the process of distribution, the confidentiality as well as integrity are required in the process of distribution. So, we propose a CRL distributing method based on group key agreement in D-OCSP. The proposed method can distribute effectively a published CRL to OCSP Responders with confidentiality as well as integrity and offer concurrency that each OCSP Responder can start CSI servicing of new CRL to clients at the same time.

• Journal of Convergence for Information Technology
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• v.7 no.6
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• pp.97-102
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• 2017

In this paper, we have interested in cooperative intelligent transport system and autonomous driving system, and focused on analysis of the characteristics of Cooperative Awareness Message (CAM) and Decentralized Environmental Notification Basis Service (DENM) message, which is key delivery message among cooperative intelligent transport system (C-ITS) characteristics for research objectivity. For research method, we also described V2X communication, and also analyzed the security certificate and header structure of CAM and DENM messages. We described CAM message, which is a message informing the position and status of the vehicle. And the DENM message is presented a message informing an event such as a vehicle accident, and analysis security communication, which is supported services. According to standard analysis result, 186 bits or 275 bits are used. In addition to the security header and the certificate format used for vehicle communication, we have gained the certificate verification procedure for vehicles and PKI characteristics for vehicles. Also We derived the characteristics and transmission capability of the security synchronization pattern required for V2X secure communication. Therefore when it is considered for communication service of DENM and CAM in the C-ITS environment, this paper may be meaningful result.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.4
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• pp.83-92
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• 2005

D-OCSP-KIS proposed by Koga and Sakurai not only reduces the number or OCSP Responder's certificate but also criers the certificate status validation about OCSP Responder to the client. Therefore, D-OCSP-KIS is an effective method that can reduce the communication cost, computational time and storage consumption in client, but it has some problems. In case an attacker accidentally acquires an OCSP Responder's session private key in a time period (e.g., one day), she can disguise as the OCSP Responder in the time period unless the OCSP Responder recognizes. She can offer the wrong response to the client using the hash value intercepted. And the server and user on I-commerce can have a serious confusion and damage. And the computation and releasing of hash chain can be a load to CA. Thus, we propose a method detecting immediately the exposure of an OCSP Responder's session private key and the abuse of hash value in D-OCSP-KIS.