• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권1호
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• pp.145-164
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• 2023

Cloud computing offers a platform that is both adaptable and scalable, making it ideal for outsourcing data for sharing. Various organizations outsource their data on cloud storage servers for availing management and sharing services. When the organizations outsource the data, they lose direct control on the data. This raises the privacy and security concerns. Cryptographic encryption methods can secure the data from the intruders as well as cloud service providers. Data owners may also specify access control policies such that only the users, who satisfy the policies, can access the data. Attribute based access control techniques are more suitable for the cloud environment as they cover large number of users coming from various domains. Multi-authority attribute-based encryption (MA-ABE) technique is one of the propitious attribute based access control technique, which allows data owner to enforce access policies on encrypted data. The main aim of this paper is to comprehensively survey various state-of-the-art MA-ABE schemes to explore different features such as attribute and key management techniques, access policy structure and its expressiveness, revocation of access rights, policy updating techniques, privacy preservation techniques, fast decryption and computation outsourcing, proxy re-encryption etc. Moreover, the paper presents feature-wise comparison of all the pertinent schemes in the field. Finally, some research challenges and directions are summarized that need to be addressed in near future.

• Journal of information and communication convergence engineering
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• 제10권2호
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• pp.156-161
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• 2012

An increasing number of people who use a smart phone or tablet PC are accessing wireless networks in public facilities including cafes and shopping centers. For example, iPhones and Android Phones have been available since 2010. However, security incidents may occur through all sorts of malicious code infection of users' personal information during the use of an insecure wireless network. In this paper, we will describe the Wi-Fi protected access (WPA) and WPA2 encryption systems used to access a wireless network from a smart phone and tablet PC, and demonstrate the access point (AP) hacking process in a wireless network to which a password is applied on the basis of the analyzed WPA and WPA2 passwords. We will analyze the method of successful AP hacking and propose an approach to enhancing wireless LAN security. This study will contribute to enhancing the security and stability of wireless networks.

• 한국컴퓨터정보학회지
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• 제14권1호
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• pp.175-184
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• 2006

이 연구에서는 유비쿼터스 컴퓨팅 환경에서 정보 보안 문제를 접근 제어 기법을 중심으로 두가지 방식에 대한 연구 형태를 분석 고찰하며, 기존 연구들의 장단점을 비교하여 유비쿼터스 환경에서의 상황 인식 서비스 플랫폼 개발시 핵심적으로 고려해야할 중요 요소를 설계할 때 필요한 레퍼런스를 제안한다. 첫 번째는, 유비쿼터스 환경에서 역할 기반 접근 제어 방식을 적용하는데 문제점을 상황 정보를 활용하여 해결하는 연구 방향에 대한 고찰이다. 두 번째는, 유비쿼터스 환경에서 상황 정보는 개인의 정보 보호에 관련해 중요한 사항이므로, 여기에 역할 기반 접근 제어 방법을 적용하여 해결하는 연구이다. 이러한 두 가지 연구 방향은 상황 인식 서비스 플랫폼 설계시 중요하게 고려해야 할 사항이다.

• 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.

• 정보처리학회논문지A
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• 제11A권7호
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• pp.563-570
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• 2004

유비쿼터스 컴퓨팅 환경은 보안의 강화와 사생활 보호라는 과제를 안고 있다. 접근 제어는 보안 분야의 하나인데, 유비쿼터스 컴퓨팅 환경은 전통적인 정보시스템과는 여러 면에서 특성을 달리하기 때문에 기존의 접근제어 모델을 그대로 적용하기에는 무리가 있다. 본 연구에서는 접근제어 측면에서 유비쿼터스 컴퓨팅 환경을 정의하고 그 환경에서 접근제어의 특성을 분석한 뒤, 그 환경을 위한 접근제어 모델을 개발할 때 필수적으로 고려해야할 요구사항을 제시하였다. 또한 접근제어 모델의 구현시 가능한 세가지 유형에 대해서도 제시하였다.

• 정보관리학회지
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• 제22권2호
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• pp.253-273
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• 2005

기존의 저널 출판 기반 학술 커뮤니케이션과 관련하여 7가지 문제점을 제시하였고 새로운 학술 커뮤니케이션 동향으로 등장한 자유이용(open access) 학술 커뮤니케이션이 이에 대한 해결책이 될 수 있음을 제시하였다. 국내에서의 자유이용 현황 파악을 위해 자유이용 관련 저널과 아카이브를 조사하였고 자유이용을 위한 라이선스와 소프트웨어 개발 현황을 조사하였다. 그리고 국내에서의 자유이용 활성화를 위한 도서관의 기대 역할을 제안하였다.

• 한국통신학회논문지
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• 제27권11C호
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• pp.1158-1163
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• 2002

In this paper it is focused on the relation between CLR (Cell Loss Ratio) and blocking probability, GoS(Grade of Services) parameters in the wireless ATM (Asynchronous Transfer Mode) access network which consists of access node and wireless channel. Traffic model of wireless ATM access network is based on the cell scale, burst scale and call connection level. The CLR equation due to buffer overflow for wireless access node is derived for CBR (Constant Bit Rate) traffic. The CLR equation due to random bit errors and burst errors for wireless channel is derived. Using the CLR equation for both access node and wireless channel, the CLR equation of wireless ATM access network is derived. The relation between access network CLR and blocking probability is analyzed for CBR traffic.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.523-526
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• 2010

FM 무전기는 반이중통신(Half-duplex)방식을 사용한다, FM 무전기를 DCE(Data Circuitterminating Equipment)로 사용하고 다수의 가입자가 정보교환을 수행하는 통신망에서 데이터 전송이 일어나고 있는지를 검출하고 데이터 전송 시 충돌을 방지하기 위해 Network Access Control을 사용한다. 본 논문에서는 현재 우리 군에서 운용하고 있는 FM무전기를 사용하는 통신망에서 MIL-STD-188-220C의 Network Access Control 방법 중 R-NAD(Random Network Access Delay)를 적용한 MPC8260 Power QUICC 기반의 디지털 메시지 전송장비에 대하여 연구한다.

• International journal of advanced smart convergence
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• 제7권4호
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• pp.66-74
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• 2018

While new information technology advances have made information access and acquisition methods much more diverse and easier, there are side effects that allow illegal access using diverse and high-performance tools. In order to cope with such threats, there are access control methods in database technology, and various studies are being conducted to extend traditional access control to cope with new computing environments. In this paper, we propose an extended access control with uncertain context-awareness. It enables appropriate security policy enforcement even if the contextual constraints specified by the security policy does not match those accompanied by access request query. We extract semantic implications from context tree, and define the argument that can quantitatively measure the semantic difference between two nodes in the context tree. It is used to semantically enforce the security policy, and to prevent the excessive authorization caused by the implication.

• Asian Journal of Business Environment
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• 제12권3호
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• pp.23-30
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• 2022

Purpose: This study aims to determine the effect of broadband access, education level, population numbers, and investment on the unemployment rate in Indonesia. Research design, data, and methodology: This study uses panel data from 34 provinces from 2016 to 2019. The analysis uses the fixed-effect model for panel data with the Feasible Generalized Least Square (FGLS) estimation method. Results: Broadband access has a negative and significant effect on the unemployment rate. Mean years of school, population, and foreign direct investment also have a negative and significant impact on the unemployment rate. In contrast, the domestic direct investment variable has a positive and significant effect. Conclusion: The availability of broadband access in an area allows easier and faster access to information. The ease of access to such information can affect producing goods and services, encouraging innovation and employment growth, and reducing the unemployment rate. This research recommends that the government intensify the Indonesia Broadband Plan policy to accelerate the development and equitable distribution of broadband access in all regions of Indonesia.