• The KIPS Transactions:PartC
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• v.19C no.1
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• pp.63-70
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• 2012

To ensure privacy of individual information in remote healthcare service, health data should be protected through a secure technology such as encryption scheme. Only user who delegated decryption right can access to sensitive health data and delegator needs capability for revocating access privilege. Recently, in ubiquitous environment, CP-ABTD(Ciphertext-Policy Attribute-Based Threshold Decryption with Flexible Delegation and Revocation of User Attributes) which extends CP-ABE(Ciphertext-Policy Attribute-Based Encryption) has been proposed for these requirements. In this paper, we construct remote healthcare monitoring system with delegation and revocation capability for attribute in CP-ABTD. Finally, we analyze collusion attack between users in our system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.1
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• pp.455-472
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• 2020

As a user in modern societies with the rapid growth of Internet environment and more complicated business flow processes in order to be effective at work and accomplish things on time when the manager of the company went for a business trip, he/she need to delegate his/her signing authorities to someone such that, the delegatee can act as a manager and sign a message on his/her behalf. In order to make the delegation process more secure and authentic, we proposed a secure and efficient identity-based proxy signcryption in cloud data sharing (SE-IDPSC-CS), which provides a secure privilege delegation mechanism for a person to delegate his/her signcryption privilege to his/her proxy agent. Our scheme allows the manager of the company to delegate his/her signcryption privilege to his/her proxy agent and the proxy agent can act as a manager and generate signcrypted messages on his/her behalf using special information called "proxy key". Then, the proxy agent uploads the signcrypted ciphertext to a cloud service provider (CSP) which can only be downloaded, decrypted and verified by an authorized user at any time from any place through the Internet. Finally, the security analysis and experiment result determine that the proposed scheme outperforms previous works in terms of functionalities and computational time.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.947-950
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• 2002

인터넷이 급속히 발달하면서 초기에 제공되던 정보제공의 방법으로는 사용자 신원에 대한 인증으로는 부족하게 되었다. 이에 대해 PKI(Public-Key Infrastructure)에서 인증서를 기반으로 사용자의 신원을 제공하는 보안방법이 대두되었다. 하지만 시스템에 따라 각 사용자에게 다른 서비스를 제공하고 이용해야 할 경우가 발생하게 되는데, 이 경우 각 사용자의 권한이나 임무 등의 사용자 속성을 관리할 필요가 있다. 이때 기존에 사용된 PKI의 확장 영역을 이용하지 않고, 새롭게 사용자 속성을 위한 인증서를 사용하게 되는데 이것을 PMI라고 한다. 본 논문에서는 PMI(Privilege Management Infrastructure)를 이용한 효율적이고 검증 가능한 권한위임 프로토콜에 대하여 제안한다.

• Journal of Digital Convergence
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• v.13 no.3
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• pp.209-214
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• 2015

Social network services such as Facebook and Flickr is a very useful service that was the foundation of the Internet. If a state in which the Internet is connected, music, photos, and us to be able to share it freely post such as documents. However, even when the digital information posted in such social network services the user has died, and have been published, it is also used for people who do not intend the bad purposes some problems can occur. Facebook is trying to apply the findings Jed R. Brubaker of UC Irvine University in order to solve this problem. However, in Korea, such efforts, not much appears for now. Therefore, we proposed a method that can be managed by delegated Facebook, safely a Delegator digital information posted on social networking services such as Flickr. Our proposed system, as compared with Jed R. Brubaker and Jeong-Kyung Moon is executed previous studies, we studied a method proposed by the appropriate compensates points shortage is passed through the future research. And I consider to have been proposed a method to safely use posted digital assets in a social network service.