• Proceedings of the IEEK Conference
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• summer
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• pp.52-56
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• 2004

Computing today is becoming ubiquitous. In such ubiquitous computing environments, entities expect to access resources and services at any time from anywhere. Therefore, the question rises of how to establish trust relationship in previously unknown devices or resources with such environment. After reviewing a model to delegate trust to communicating entities in ubiquitous environment and its security problems, we present a new model for secure delegation over communication entities. We adopt two-party signature scheme as cryptographic primitives. Additionally, we apply threshold cryptosystems to our model for more secure enhancement.

• Journal of the Korea Safety Management & Science
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• v.13 no.4
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• pp.171-177
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• 2011

This paper reviewed the relationship between internal marketing and incremental innovation, and the moderating effect of firm size. The results of hierarchical multiple regression analysis, based on the responses from 322 employees in small business, showed that almost internal marketing factors effects positively on incremental innovation. All internal marketing factors(CEO support, compensation system, education & training, internal communication, authority delegation) appeared to be related positively with process innovation and service innovation. And all other factors(compensation system, education & training, internal communication, authority delegation) except CEO support showed to have positive relationship with operation innovation. In the moderating effects, internal communication effects more positively on incremental innovation in large firm-size than in small firm-size. But delegation effects more positively on incremental innovation in small firm-size than in large firm-size.

• Journal of the Korea Computer Industry Society
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• v.10 no.1
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• pp.21-28
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• 2009

Role-Based Access Control Policy has a role hierarchies in which a higher case role can perform permissions of a lower case role. However, it is necessary for a lower case role to perform a higher case role's permission, which is not allowed to a lower case role, basically. In this paper propose a temporary permission delegation method. As the result of a temporary permission delegation, junior roles can perform senior roles' permissions in a dedicated interval.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.8
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• pp.465-472
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• 2004

Proxy signatures is a signature scheme that an original signer delegates one's signature capability to a proxy signer, and then the proxy signer creates a signature on behalf of the original signer. Delegation of authority is a common practice in the real world, in particular, it happens naturally in hierarchical groups such as company, bank and army, etc. In this paper, we propose a new dynamic multi-proxy signature scheme allowing repetitive delegations in a hierarchical group. We adopt multi-proxy signatures to enhance the security of proxy signature. In multi-proxy signatures, plural proxy signers can generate a valid proxy signature collectively on behalf of one original signer. In our scheme, the proxy group is not fixed but constructed dynamically according to some situations. Delegations are processed from higher level to lower level in the hierarchy using delegation tickets. When the original signer wants to delegate one's signature authority, the original signer generates a delegation ticket based on secret sharing and Diffie-Hellman problems. The delegation ticket is shared among proxy signers and then all the proxy signers can generate a valid proxy signature collectively by reconstructing the original signer's delegation ticket. If a certain proxy signer can not attend the proxy signature generating protocol, the proxy signer can also delegate repetitively his partial signature authority to the lower level participants, and then the proxies are constructed dynamically.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.279-282
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• 2015

Energy Technology Perspectives (ETP) has provided the current status of energy system, technology developments and external events that have changed ETP scenario since 2006. The three scenarios are presented in four different fields (power generation, transport, industry, building). Energy efficiency improvement of energy system and the new system that can solve the increasing energy demand and the emissions are introduced. The activities on IEA/ECERC delegation of Korea will be also reported in this presentation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.1
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• pp.91-98
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• 2010

This paper proposes authority delegation for secure social community creation and mutual authentication scheme between the community members using proxy signature in community-based ubiquitous networks. In community-based ubiquitous network, User's context-awareness information is collected and used to provide context-awareness network service and application service for someone who need it. For the many reason, i.e. study, game, information sharing, business and conference, social community could be created by members of a social group. However, in community-based ubiquitous network, this kind of the context-awareness information could be abused and created by a malicious nodes for attack the community. Also, forgery community could be built up to attack the community members. The proposed scheme using the proxy signature provides a mutual authentication and secure secret key exchange between community members, and supports secure authority delegation that can creates social community. Also, when delegation of signing authority and mutual authentication, this scheme reduces total computation time compared to the RSA signature scheme.

• Journal of Families and Better Life
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• v.18 no.2
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• pp.109-123
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• 2000

The purpose of this study is to investigate decision making styles task management of urban homemakers. This study focuses on the following aspects: 1) to find out which variables of background variables (ie. age of couple, education of couple, duration of marriage, income, family life cycle, number of children) have effect on decision making styles & task management of urban homemakers. 2) to find out the relationships between decision making styles and task management of urban homemakers. 3) to find out independent influcene of background variables on task management. major findings are as follows; First, it is general tendency that decision making styles were human oriented in urban homemakers. Importance & Urgency of the task, age of homemakers, education of homemakers, family life cycle were significant variables to have influcence on task oriented decision making styles. Importance & urgency of task were variables to have influences on human oriented decision making styl s. Second, the tendency of dealing with task at once is the highest in the task management, on the other hand, the tendency of dealing with task in the next session is the lowest. Income is a variable to influence on dealing with task in delegation to others, education of homemaker is a variable to influence on dealing with task in next session and importance & urgency of the task and the number of children were variables to influence on dealing with task immediately. Third, human oriented decision marking style was a variable to influence on dealing with task in delegation with task in delegation to others, in the next session, and in suspending/ in neglecting. Task oriented decision making style was a variable to influence on dealing with task immediately. Fourth, The urgency of task & income were variables to have direct influence on dealing with task in delegation with task in next session, and the urgency of the task, age & education of homemaker and family life cycle were varia les to direct influence on dealing with the task immediately. The urgency & importance of the task and age of homemaker were variables to have indirect on dealing with the task urgency of task & the number of children were variables to have indirect influence on dealing with the task in suspending/in neglecting through the medium of the human oriented decision making styles.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.4
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• pp.111-122
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• 2008

Web service is defined to support interoperable machine to machine interaction over a network and defined as distributed technologies. Recently in web service environment, security has become one of the most critical issues. An attacker may expose user privacy and service information without authentication. Furthermore, the users of web services must temporarily delegate some or all of their behalf. This results in the exposure of user privacy information by agents. We propose a delegation model for providing safety of web service and user privacy in ubiquitous computing environments. In order to provide safety of web service and user privacy, XML-based encryption and a digital signature mechanism need to be efficiently integrated. In this paper, we propose web service management server based on XACML, in order to manage services and policies of web service providers. For this purpose, we extend SAML to declare delegation assertions transferred to web service providers by delegation among agents.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.4
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• pp.129-138
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• 2003

Role-Based Access Control(RBAC) model is becoming a promising model for enterprise environments with various organization structures. In terms of role hierarchy, each senior role inherits all the permissions of its junior roles in the role hierarchy, and a user who is a member of senior role is authorized to carry out the inherited permissions as well as his/her own ones. But there is a possibility for senior role members to abuse permissions. Since senior role members need not have all the authority of junior roles in the real world, enterprise environments require a restricted inheritance rather than a unconditional or blocked inheritance. In this paper, we propose a new role-based delegation model using the role hierarchy model with restricted inheritance functionality, in which security administrator can easily control permission inheritance behavior using sub-roles. Also, we describe how role-based user-to-user, role-to-role delegations are accomplished in the model and the characteristics of the proposed role-based delegation model.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.6
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• pp.1103-1113
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• 2020

Hospitals store and manage personal and health information through the electronic medical record (EMR). However, vulnerabilities and threats are increasing with the provision of various services for information sharing in hospitals. Therefore, in this paper, we propose a model to prevent personal information leakage due to the transmission of patient information in EMR. A method for granting permission to securely receive and transmit patient information from hospitals where patient medical records are stored is proposed using OAuth authorization tokens. A protocol was proposed to enable secure information delivery by applying and delivering the record access restrictions desired by the patient to the OAuth Token. OAuth Delegation Token can be delivered by writing the authority, scope, and time of destruction to view patient information.This prevents the illegal collection of patient information and prevents the leakage of personal information that may occur during the delivery process.