• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.837-840
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• 2000

For secure communications in using multicast applications such as Cable-TV, It is essential for us to manage shared keys to encrypt/decrypt data through crypto algorithm as DES, which is called Group Key Management. In GKM, It is a hot issue that reduces the number of join/leave operation and subgroup key in key tree model. In this paper, we propose optimized mechanism of group key management required for providing multicast security.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10C
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• pp.1011-1022
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• 2006

WSN(Wireless Sensor Network) performs to detect and collect environmental information for one purpose. The WSN is composed of a sink node and several sensor nodes and has a constraint in an aspect of energy consumption caused by limited battery resource. So many required mechanisms in WSN should consider the remaining energy condition. To deploy WSN, tile collected information is required to protect from an adversary over the network in many cases. The security mechanism should be provided for collecting the information over the network. we propose asynchronized key management considering energy efficiency over WSN. The proposed key management is focused on independence and difference of the keys used to deliver the information over several routes over the network, so disclosure of any key does not results in exposure of total key information over the overall WSN. Also, we use hash function to update key information for energy efficiency Periodically. We define the insecurity for requested security Properties and Proof that the security properties are guaranteed. Also, we evaluate and analyze the energy efficiency for the proposed mechanism.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.7 s.349
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• pp.1-13
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• 2006

In this paper, we introduce a novel key management scheme that is based on the key pre-distribution but provides the key re-distribution method, in order to manage keys for message encryption and authentication of lower-layer sensor nodes on hierarchical mobile sensor networks. The characteristics of our key management are as follows: First, the role of key management is distributed to aggregator nodes as well as a sink node, to overcome the weakness of centralized management. Second, a sink node generates keys using regression model, thus it stores only the information for calculating the keys using the key information received from nodes, but does not store the relationship between a node and a key, and the keys themselves. As the disadvantage of existing key pre-distributions, they do not support the key re-distribution after the deployment of nodes, and it is hard to extend the key information in the case that sensor nodes in the network enlarge. Thirdly, our mechanism provides the resilience to node capture(${\lambda}$-security), also provided by the existing key pre-distributions, and fourth offers the key freshness through key re-distribution, key distribution to mobile nodes, and scalability to make up for the weak points in the existing key pre-distributions. Fifth, our mechanism does not fix the relationship between a node and a key, thus supports the anonymity and untraceability of mobile nodes. Lastly, we compare ours with existing mechanisms, and verify our performance through the overhead analysis of communication, computation, and memory.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.5
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• pp.899-914
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• 2022

A blockchain-based decentralized service can offer reliable services without the centralized server by operating the system based on the consensus among byzantine participants. Participants can interact with the blockchain network through a digital signature mechanism but the private key management issue remains unresolved. NIST SP800-57 provides a key-management guidance but this guidance is not appropriate for blockchain-based services because it does not consider a decentralized environment. In this paper, we define the core functions of the blockchain wallet application for private key management and present security protections according to NIST SP800-57, as well as related techniques to satisfy them. Finally, we propose the private key management guideline for secure blockchain-based decentralized services.

• Journal of Advanced Navigation Technology
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• v.16 no.4
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• pp.679-686
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• 2012

Many researches have proposed key management schemes for Smartgrid System. However, previous studies lack the proper considerations for availability and device security. In this paper, we build up cryptographic security improvement for robust Smartgrid Systems. In addition, we propose a public-key management and hash function architecture for robust Smartgrid Systems which supports reduces the number of key and Secure Device in AMI network environments.

• Journal of Distribution Science
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• v.11 no.6
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• pp.59-65
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• 2013

Purpose - Studies of mechanism as a competitive strategy, a relatively new field in the study of strategic management research, has recently drawn the attention of the business management scholars. The literature has so far proposed the subjective-based view, environment-based view, and the resource-based view in its analyses of firm management. Hence, it is highly likely for the firm management to be reasonably thought of as a combination of and interaction among the three key elements of subject, environment, and resources this is the mechanism-based view (MBV). It is reasonable to consider firm management to be the combination of and interaction among the three key elements of subject, environment, and resources. The overall dynamic process that integrates these three elements and creates functional harmony is identified as the mechanism, the principle of firm management. Much of the extant literatures on MBV has mainly focused on case studies, a qualitative approach prone to subjectivity of the researcher, although the intuition from the study may lead to meaningful insights into a firm-specific mechanism. This study's focus is also on case analysis, but it still attempts a quantitative approach in order to reach a scientific and systematic understanding of the MBV. Research design, data, and methodology - I used both a qualitative and quantitative approach to a single model, given the complexity of the innovation processes. I conducted in-depth interviews with POSCO employees-20 from general management, two from human resources, eight from information technology, five from finance and accounting, and five from production and logistics management. Once the innovative events were selected, the interview results were double-checked by the interviewees themselves to ensure the accuracy of the answers recorded. Based on the interview, I then conducted statistical validation using the survey results as well. Results - This study analyzes the building process of innovation and the effect of the mechanism pattern on innovation by examining the case of POSCO, which has survived over the past 21 years. I apply a new analytical tool to study mechanism innovation types, perform a new classification, and describe the interrelationships among the mechanism factors. This process allows me to see how the "Subject"factor interacts with the other factors. I found that, in the innovation process of the adoption stage, Subject had a mediating effect but that the mediating effect of resource and performance was smaller than the effect of Subject on performance alone. During the implementation stage, the mediating effect of Subject increased. Conclusion - Therefore, I have confirmed that the subject utilizes resources reasonably and efficiently. I have also advanced mechanism studies: whereas the field's research methods have been largely confined to single case studies, I have used both qualitative and quantitative methods to examine the relationships among mechanisms.

• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2063-2072
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• 2013

Smart Grid is the next-generation intelligent power grid that maximizes energy efficiency with the convergence of IT technologies and the existing power grid. It enables consumers to check power rates in real time for active power consumption. It also enables suppliers to measure their expected power generation load, which stabilizes the operation of the power system. However, there are high possibility that various kinds of security threats such as data exposure, data theft, and privacy invasion may occur in interactive communication with intelligent devices. Therefore, to establish a secure environment for responding to such security threat with the smart grid, the key management technique, which is the core of the development of a security mechanism, is required. Using a hash chain, this paper suggests a group key management mechanism that is efficiently applicable to the smart grid environment with its hierarchical structure, and analyzes the security and efficiency of the suggested group key management framework.

• 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.

• Korea Journal of Hospital Management
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• v.14 no.4
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• pp.1-24
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• 2009

The purpose of this study was to find out the differences and relationships among balanced strategy, coordinating and learning mechanism, and perceived performance of hospitals in Korea, and provide some directions to establish effective strategic management of hospital. Measure items on balanced strategy, coordinating and learning mechanism, and perceived performance were developed from previous studies. Questionnaire was sent and received through Internet site and e-mail during May, 2008. Data were collected from key informant in each institutions, and analyzed using frequency analysis, T-test, ANOVA, correlation and regression analysis. The major findings of this study were as follows: 1. The level of strategic selection and external learning mechanism of private hospital was lower than that of medical corporation, and others corporation hospital. 2. There was little difference between hospitals in metropolitan and those in small cities. 3. Hospitals that have under 100 beds were statistically lower level in strategic selection and external learning mechanism than hospitals has over 100 beds. 4. Formal coordinating and external learning mechanism, and foundation form(medical corporation) were significantly influenced on profitability from specialized field. 5. Strategic selection and adaptation mechanism were significantly affected on total profitability. 6. Strategic selection and external learning mechanism were significantly influenced on competitive power around its local market. Hospitals that are to be competitive by specialization should have to establish mechanism for management such as balanced strategy, coordinating and learning mechanism.