• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.5
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• pp.27-38
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• 2007

One of the most important security issues of e-mail service is user privacy. Currently, various security protocols, like PGP(pretty Good Privacy), S/MIME(Secure/Multipurpose Internet Mail Extension), have been proposed. These protocols, however, do not provide forward secrecy. Recently, some security protocols that provide forward secrecy were proposed. But all of them require changes to the current e-mail infrastructure. Moreover, contrary to authors' intention, some of them do not actually provide perfect forward secrecy. In this paper, we propose a new practical e-mail security protocol. The proposed protocol provides perfect forward secrecy and uses a practical e-mail model that dose not require any changes to existing e-mail servers. It encrypts and authenticates messages efficiently using elliptic curve based signcryption scheme. In addition, we provide a way to send secure group e-mails.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.5
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• pp.53-61
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• 2002

In this paper, we will introduce a design of key recovery based on XML can be used in B2B environment. XML Digital Signature and XML Encryption that are defied recently as standards by W3C(World Wide Web Consortium) are deployed to sign/verify or encrypt/decrypt documents for electronic commerce and keys to store/load at/from key recovery server. The result of signature or encryption is always an XML document and all messages used in this key recovery system are also XML documents. It enables to adapt transparently this key recovery system to legacy XML applications and electronic commerce platforms based on XML. And its method for key recovery is key escrow. One of the characteristics of this key recovery is that one enterprise can recover keys of some documents for electronic commerce from external key recovery system in other enterprises related with them and also recover keys from owns.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.3
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• pp.71-79
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• 2003

Existing web-based system management software solutions show some limitations in time and space. Moreover, hey possess such as shortcomings unreliable error message announcements and difficulties with real-time assistance supports and emergency measures. In order to solve these deficiencies, Wireless Remote Control System(W-RCS) was designed and implemented. W-RCS is able to manage and monitor remote systems by using mobile communication devices for instantaneous control. The implementation of W-RCS leads to these security problems as well as solutions to aforementioned issues with existing web-based system management software solutions. Therefore, this paper has focused on the security matters related to W-RCS. The security functions based on public key infrastructure include mobile device user authentication and target system access control. The W-RCS allows real-time user authentication, increases the flexibility of resource administrators and mobile device non, and provides not only uninterrupted services, but also safe mobile office environments.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.6
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• pp.173-186
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• 2003

Distributed Denial-of-Service(DDoS) attack prevent users from accessing services on the target network by spoofing its origin source address with a large volume of traffic. The objective of IP Traceback is to determine the real attack sources, as well as the full path taken by the attack packets. Existing IP Traceback methods can be categorized as proactive or reactive dating. Proactive tracing(such as packet marking and messaging) prepares information for tracing when packets are in transit. Reactive tracing starts tracing after an attack is detected. In this paper, we propose a 'advanced ICW Traceback' mechanism, which is based on the modified pushback system with secure router mechanism. Proposed mechanism can detect and control DDoS traffic on router and can generate ICMP Traceback message for reconstructing origin attack source, by which we can diminish network overload and enhance Traceback performance.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.6
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• pp.71-82
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• 2009

There have been a lot of researches on providing privacy in MANET (Mobile Ad hoc NETwork) using trapdoor, onion, and anonymous authentication. Privacy protection in MANET can be divided into satisfying ID privacy, location privacy, route privacy, and unlinkability between sessions. Most of the previous works, however, were unsatisfactory with respect to location privacy or route privacy. Moreover, in previous schemes, cryptographic operation cost needed to meet the privacy requirements was relatively high. In this paper, we propose a new efficient anonymous routing protocol that satisfies all the privacy requirements and reduces operation costs. The proposed scheme does not use onion or anonymous authentication techniques in providing privacy. We also provide a more accurate analysis of our scheme's efficiency by considering all the nodes involved in the route establishment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.3
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• pp.121-134
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• 2010

With the help of various Layer 2 triggers, Fast Handover for Mobile IPv6 (FMIPv6) considerably reduces the latency and the signaling messages incurred by the handover. Obviously, if not secured, the protocol is exposed to various security threats and attacks. In order to protect FMIPv6, several security protocols have been proposed. To our best knowledge, there is lack of analysis and comparison study on them though the security in FMIPv6 is recognized to be important. Motivated by this, we provide an overview of the security protocols for FMIPv6, followed by the comparison analysis on them. Also, the security threats and requirements are outlined before the protocols are explored. The comparison analysis result shows that the protocol presented by You, Sakurai and Hori is more secure than others while not resulting in high computation overhead. Finally, we introduce Proxy MIPv6 and its fast handover enhancements, then emphasizing the need for a proper security mechanism for them as a future work.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.1
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• pp.93-104
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• 2011

A conditional access system is an essential element in IPTV services enabling service providers to allow authorized access to their services only to paid subscribers. Currently, there are two types of IPTV service models, namely PPC (pay-per-channel) and PPV (pay-per-view). However, a more desirable model would be the flexible PPC model, in which subscribers are free to choose any combination of preferred channels and add/remove channels independently. In this paper, we first point out that a previously proposed key management scheme for F-PPC is not secure. We then propose a new conditional access system using 4-level key hierarchy to realize secure F-PPC services. Compared to existing schemes, the proposed system is very efficient, just requiring O(1) communication for key update.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.5
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• pp.89-98
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• 2010

Wireless LAN (WLAN) is type of wireless service that has higher data transmission than current cellular networks. The usage is continually increasing. There are a lot of vulnerabilities in wireless network, due to the properties of the wireless environment, regardless of its popularity. IEEE announced the 802.11i security standard to solve these problems. The vulnerable point of messages used in the process of key distribution for 802.11i makes the target node attacked lose memory through continuous messages and blocks the legitimate WLAN service. In this paper, we proposed new schemes to solve this problem and compared our proposals with the current process. The proposed protocol eliminates the memory exhaustion problem on the client side by using methods for reduction of memory usage.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.1
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• pp.17-31
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• 2010

In VANET (Vehicular Ad hoc NETwork), vehicles can efficiently verify a large number of signatures efficiently using batch verification techniques. However, batch verification performed independently in each vehicle raises many redundant verification cost. Although, an RSU (Road Side Unit) can perform the batch verification as a proxy to reduce this cost, it additionally requires an efficient method to identify invalid signatures when the batch verification fails. In this paper, we analyze several ways of constructing a distributed batch verification system, and propose an efficient distributed batch verification system in which participating vehicles perform batch verification in a distributive manner for a small size signature set. In our proposed system, each node can report the batch verification result or the identified invalid signatures list and the RSU who received these reports can identify the invalid signatures and efficiently exclude them.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.6
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• pp.83-89
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• 2022

Internet of Things technology is rapidly developing due to the recent development of information and communication technology. IoT technology utilizes various sensors to generate unique data from each sensor, enabling diagnosis of system status. However, the equipment management system currently in effect is a post-preservation concept in which administrators must deal with the problem after the problem occurs, which could mean system reliability and availability problems due to system errors, and could result in economic losses due to negative productivity disruptions. Therefore, this study confirmed that edge controller control decision algorithms for more efficient operation of rectifiers in the factory by applying intelligent IoT (AIoT) technology and domain knowledge-based modeling for each sensor data collected based on this, outputting appropriate status messages for each scenario.