• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2001년도 봄 학술발표논문집 Vol.28 No.1 (A)
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• pp.820-822
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• 2001

전자상거래가 활발하게 이루어짐으로서 지불사단에 대한 관심이 증가되고 있다. 또한 지불 시스템에 대한 수많은 연구가 진행되고 있다. 특히 사용자의 사생활을 보호하기 위해 익명성을 제공하는 시스템과 이로 인해 발생하는 문제점을 해결하기 위해 익명성 제어에 관련된 전자화폐 시스템이 연구되고 있다. 따라서 본 논문에서는 국내 전자서명 표준은 KCDSA를 기반을 하여 익명성을 유지하며 실물화폐에서 갖지 못한 효율적이고 편리한 분할성 기능과 필요시 신뢰기관의 도움으로 익명성을 제어할 수 있는 새로운 전자화폐 시스템을 제안한다.

• International Journal of Computer Science & Network Security
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• 제23권2호
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• pp.31-38
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• 2023

In the current Internet system, there are many problems using anonymity of the network communication such as personal information leaks and crimes using the Internet system. This is why TCP/IP protocol used in Internet system does not have the user identification information on the communication data, and it is difficult to supervise the user performing the above acts immediately. As a study for solving the above problem, there is the study of Policy Based Network Management (PBNM). This is the scheme for managing a whole Local Area Network (LAN) through communication control for every user. In this PBNM, two types of schemes exist. As one scheme, we have studied theoretically about the Destination Addressing Control System (DACS) Scheme with affinity with existing internet. By applying this DACS Scheme to Internet system management, we will realize the policy-based Internet system management. In this paper, required functions in the PBNM Scheme for multiple domains as cyber physical system that utilizes data science and AI is examined.

• International Journal of Computer Science & Network Security
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• 제23권1호
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• pp.71-77
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• 2023

In the current Internet system, there are many problems using anonymity of the network communication such as personal information leaks and crimes using the Internet system. This is why TCP/IP protocol used in Internet system does not have the user identification information on the communication data, and it is difficult to supervise the user performing the above acts immediately. As a study for solving the above problem, there is the study of Policy Based Network Management (PBNM). This is the scheme for managing a whole Local Area Network (LAN) through communication control for every user. In this PBNM, two types of schemes exist. As one scheme, we have studied theoretically about the Destination Addressing Control System (DACS) Scheme with affinity with existing internet. By applying this DACS Scheme to Internet system management, we will realize the policy-based Internet system management. In this paper, to realize it, concept of the Internet PBNM Scheme is proposed as the final step.

• International Journal of Computer Science & Network Security
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• 제23권11호
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• pp.1-7
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• 2023

In the current Internet system, there are many problems using anonymity of the network communication such as personal information leaks and crimes using the Internet system. This is why TCP/IP protocol used in Internet system does not have the user identification information on the communication data, and it is difficult to supervise the user performing the above acts immediately. As a study for solving the above problem, there is the study of Policy Based Network Management (PBNM). This is the scheme for managing a whole Local Area Network (LAN) through communication control for every user. In this PBNM, two types of schemes exist. As one scheme, we have studied theoretically about the Destination Addressing Control System (DACS) Scheme with affinity with existing internet. By applying this DACS Scheme to Internet system management, we will realize the policy-based Internet system management. In this paper, basic system design for PBNM scheme for multi-domain management utilizing data science and AI is proposed.

• 전자공학회논문지CI
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• 제46권1호
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• pp.78-87
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• 2009

속성 기반 서명(Attribute-Based Signature) 기법이란 서명자의 비밀키에 속성 집합(Attribute Set)이 연관되고 서명에 접근구조(Access Structure)가 연관되는 서명 기법이다. 속성 기반 서명 기법은 객체의 식별자가 속성 집합으로 표현되는 속성 기반 시스템(Attribute-Based System) 또는 권한 기반 시스템(Role-Based System)에서 서명자의 익명성과 접근 제어를 가능하게 하는 유용한 서명 기법이다. 본 논문에서는 속성 기반 서명 기법을 정의하고 서명에 포함되는 정책을 DNF(Disjunctive Normal Form) 수식으로 표현이 가능한 효율적인 속성 기반 서명 기법을 제시한다. 제시한 기법은 서명 검증시 상수번의 페어링 연산만이 필요한 최초의 안전한 기법이다. 그리고 증명이 가능한 속성 기반 서명 기법을 구성하기 위해서 새로운 interactive 가정을 소개하고 제안된 기법이 랜덤 오라클과 새로운 가정에서 안전함을 보인다.

• 한국정보시스템학회지:정보시스템연구
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• 제23권2호
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• pp.91-107
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• 2014

In computer-mediated idea generation where contributions can be anonymous, the ability to accurately monitor performances is limited, inducing social loafing. Prior research has suggested that social loafing is likely an important factor in reducing task performance. Researchers have theorized that loafing could be minimized if clear performance feedback is provided. Our prior study evidences a substantial performance gain by the provision of real time performance information about who is contributing and who is not. However, our prior study incorporated the quantity feedback only to create a larger pool of ideas based on the long-standing assumption (i.e., quantity breeds quality), not considering the quality feedback. As a result, taking advantage of anonymity in the form of pseudonymity, individuals in almost all groups exhibited a tendency of self-presentation by capitalizing on ideas of which quality was low and even frivolous (i.e., junk comments) toward the later stages of the session. Thus, we have learned that the quantity performance feedback alone does not have enough restrictiveness to consistently control the performance behavior throughout the session. Since a process chart allows participants to monitor process variation by comparing new performance data to past performance data, we incorporated real-time visual process performance feedback to reveal performance histories by connecting the sequence of idea quality scores in a time-series format. Using this environment, a laboratory experiment was conducted with five-member groups that examined the influence of both identifiability (i.e., anonymity versus pseudonymity) and process performance feedback (i.e., yes or no) in a $2{\times}2$ factorial design. The result showed that groups in the process performance feedback treatment outperformed groups in the no feedback treatment. Additionally, process performance feedback and identifiability interacted such that groups in the process performance feedback/pseudonymity treatment had the highest performance. The implications of these findings for future research, as well as the implications for the design of group idea generation procedures are discussed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2101-2105
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• 2003

Recently the number of Internet users has very sharply increased, and the number of intrusions has also increased very much. Consequently, security products are being developed and adapted to prevent systems and networks from being hacked and intruded. Even if security products are adapted, however, hackers can still attack a system and get a special authorization because the security products cannot prevent a system and network from every instance of hacking and intrusion. Therefore, the researchers have focused on an active hacking prevention method, and they have tried to develop a traceback system that can find the real location of an attacker. At present, however, because of the characteristics of Internet - diversity, anonymity - the real-time traceback is very difficult. To over-come this problem the Network-based Real-Time Connection Traceback System (NRCTS) was proposed. But there is a security problem that the victim system can be hacked during the traceback. So, in this paper, we propose modified NRCTS with connection redirection technique. We call this traceback system as Connection Redirected Network-based Real-Time Connection Traceback System (CR-NRCTS).

• International Journal of Contents
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• 제8권3호
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• pp.79-82
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• 2012

In digital contents distribution environments, a user authentication is an important security primitive to allow only authenticated user to use right services by checking the validity of membership. For example, in Internet Protocol Television (IPTV) environments, it is required to provide an access control according to the policy of content provider. Remote user authentication and key agreement scheme is used to validate the contents accessibility of a user. We propose a novel user authentication scheme using smart cards providing a secure access to multimedia contents service. Each user is authenticated using a subset of attributes which are issued in the registration phase without revealing individual's identity. Our scheme provides the anonymous authentication and the various permissions according to the combination of attributes which are assigned to each user. In spite of more functionality, the result of performance analysis shows that the computation and communication cost is very low. Using this scheme, the security of contents distribution environments in the client-server model can be significantly improved.

• 한국데이타베이스학회:학술대회논문집
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• 한국데이타베이스학회 2000년도 추계학술대회 E-Business와 정보보안
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• pp.239-248
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• 2000

전자화폐 시스템은 인출(withdrawal), 지불(payment) 그리고 예치(deposit)의 기본적인 과정을 수행하는데, 이러한 단계에서 사용자의 사생활(privacy)을 보호하기 위해 사용자와 사용자의 구입 내용 및 지불 내용을 연계시키지 않고 인출 단계와 지불 단계가 연결되지 않도록 기본적으로 익명성을 제공하고 있다. 하지만 이러한 완전한 익명성을 제공하므로 인해 돈 세탁, 약탈, 불법 거래와 같은 불법적인 범죄 행위들에 이용 될 수 있으며 이 때 이와 같은 범죄행위를 한 사용자와 그 돈에 대한 행방을 찾을 수가 없다. 따라서 이를 방지하기 위해 일정한 조건 아래에서 익명성을 제어하기 위한 연구들이 많이 진행되어 왔다. 본 논문에서는 DSS에 기반한 새로운 공정한 은닉 서명 방식을 제안하고 이를 전자화폐 시스템에 적용시킨다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권5호
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• pp.2768-2780
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• 2019

Ciphertext-policy attribute-based encryption (CP-ABE) is one of the practical technologies to share data over cloud since it can protect data confidentiality and support fine-grained access control on the encrypted data. However, most of the previous schemes only focus on data confidentiality without considering data receiver privacy preserving. Recently, Li et al.(in TIIS, 10(7), 2016.7) proposed a CP-ABE with hidden access policy and testing, where they declare their scheme achieves privacy preserving for the encryptor and decryptor, and also has high decryption efficiency. Unfortunately, in this paper, we show that their scheme fails to achieve hidden access policy at first. It means that any adversary can obtain access policy information by a simple decisional Diffie-Hellman test (DDH-test) attack. Then we give a method to overcome this shortcoming. Security and performance analyses show that the proposed scheme not only achieves the privacy protection for users, but also has higher efficiency than the original one.