• Journal of Communications and Networks
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• v.2 no.1
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• pp.46-57
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• 2000

Ongoing standardization effort on 3G cellular system in 3GPP (UNTS) is based on GPRS core network and promises a global standard for systems capable of offering ubiquitous access to internet for mobile users. Considered radio access systems(FDD CDMA, TDD CDMA, and EDGE) are optimized for robust mobile use. However, there are alternative relatively high-rate radio interfaces being standardized for WLAN (IEEE802.11 and HIPER-LAN/2) which are capable of delivering significantly higher data rates to static or semi-static terminals with much less overhead. Also WPANs(BLUETOOTH, IEEE802.15), which will be present in virtually every mobile handset in the near future, are offering low cast and considerable access data rate and thus are very attractive for interworking scenarios. The prospect of using these interfaces as alternative RANs inthe modular UMTS architecture is very promising. Additionally, the recent inclusion of M-IP in the UMTS R99 standard opens the way for IP-level interfacing to the core network. This article offers an overview into WLAN-Cellular interworking. A brief overview of GPRS, UMTS cellular architectures and relevant WLAN standards is given. Possible interworking architectures are presented.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.211-219
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• 2008

This paper is proposed context-aware based access control, model by extending original access control model. In this paper, we survey the recent researches about security model based context-aware such as xoRBAC and CAAC. For exactly policy evaluation, we make an addition Context Broker and Finder in existing CAAC security model. By this security model, Context information and context decision information is able to be collected easily for more correct policy decision. This paper controlled access of possible every resources that is able to access by user's event and constraint from primitive access resources. In this paper proposed security model can be offer dynamically various security level and access authority method alone with specified policy and constraint adjustment at user's role.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.1
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• pp.35-41
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• 2016

Internet of Things (IoT) services are widely used in appliances of daily life and industries. IoT services also provide various conveniences to users and are expected to affect value added of all industries and national competitiveness. However, a variety of security threats are increased in IoT environments and lowers reliability of IoT devices and services that make some obstacles for commercialization. The attacks arising in IoT environments are making industrial and normal life accidents unlike existing information leak and monetary damages, and can expand damage scale of leakage of personal information and privacy more than existing them. To solve these problems, we design a session key based access control scheme for secure communications in IoT environments. The proposed scheme reinforces message security by generating session key between device and access control network system. We analyzed the stability of the proposed access scheme in terms of data forgery and corruption, unauthorized access, information disclosure, privacy violations, and denial of service attacks. And we also evaluated the proposed scheme in terms of permission settings, privacy indemnity, data confidentiality and integrity, authentication, and access control.

• Journal of Internet Computing and Services
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• v.19 no.2
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• pp.27-32
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• 2018

In industries that are operating various enterprise systems, new systems are integrated and operated in accordance with each period. In particular, when a new system is to be integrated, one of the major considerations is the single sign-on part for integrating and operating the authentication. To implement this authority system using role-based access control method, an extension method for access control method is needed. Therefore, in this paper, we design an extended role-based access control model for interworking with legacy authority system and provide its APIs. The extended role-based access control model is a model in which external authority information, which holds authority information in the authority information, is added. And we describe operations that the REST Web APIs are based on these models. In this paper, the method is described in the back-end APIs and can be implemented as an operation of an extended role-based access control system based on the method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.5
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• pp.1532-1553
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• 2014

Radio spectrum is a precious resource and characterized by fixed allocation policy. However, a large portion of the allocated radio spectrum is underutilized. Conversely, the rapid development of ubiquitous wireless technologies increases the demand for radio spectrum. Cognitive Radio (CR) methodologies have been introduced as a promising approach in detecting the white spaces, allowing the unlicensed users to use the licensed spectrum thus realizing Dynamic Spectrum Access (DSA) in an effective manner. This paper proposes a generalized framework for DSA between the licensed (primary) and unlicensed (secondary) users based on Continuous Time Markov Chain (CTMC) model. We present a spectrum access scheme in the presence of sensing errors based on CTMC which aims to attain optimum spectrum access probabilities for the secondary users. The primary user occupancy is identified by spectrum sensing algorithms and the sensing errors are captured in the form of false alarm and mis-detection. Simulation results show the effectiveness of the proposed spectrum access scheme in terms of the throughput attained by the secondary users, throughput optimization using optimum access probabilities, probability of interference with increasing number of secondary users. The efficacy of the algorithm is analyzed for both imperfect spectrum sensing and perfect spectrum sensing.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2754-2767
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• 2019

Cloud computing is widely used in information spreading and processing, which has provided a easy and quick way for users to access data and retrieve service. Generally, in order to prevent the leakage of the information, the data in cloud is transferred in the encrypted form. As one of the traditional security technologies, access control is an important part for cloud security. However, the current access control schemes are not suitable for cloud, thus, it is a vital problem to design an access control scheme which should take account of complex factors to satisfy the various requirements for cipher text protection. We present a novel access control scheme based on proxy re-encryption(PRE) technology (PreBAC) for cipher text. It will suitable for the protection of data confidently and information privacy. At first, We will give the motivations and related works, and then specify system model for our scheme. Secondly, the algorithms are given and security of our scheme is proved. Finally, the comparisons between other schemes are made to show the advantages of PreBAC.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.11
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• pp.3892-3912
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• 2021

The recent rapid growth of mobile network traffic places multi-access edge computing in an important position to reduce network load and improve network capacity and service quality. Contrasting with traditional mobile cloud computing, multi-access edge computing includes a base station cooperative cache layer and user cooperative cache layer. Selecting the most appropriate cache content according to actual needs and determining the most appropriate location to optimize the cache performance have emerged as serious issues in multi-access edge computing that must be solved urgently. For this reason, a cache placement algorithm based on comprehensive utility in big data multi-access edge computing (CPBCU) is proposed in this work. Firstly, the cache value generated by cache placement is calculated using the cache capacity, data popularity, and node replacement rate. Secondly, the cache placement problem is then modeled according to the cache value, data object acquisition, and replacement cost. The cache placement model is then transformed into a combinatorial optimization problem and the cache objects are placed on the appropriate data nodes using tabu search algorithm. Finally, to verify the feasibility and effectiveness of the algorithm, a multi-access edge computing experimental environment is built. Experimental results show that CPBCU provides a significant improvement in cache service rate, data response time, and replacement number compared with other cache placement algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.1
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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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.8A
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• pp.1213-1222
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• 2000

We have considered and developed a subsystem of switching system which provides Internet access service, taking into considerations of traffic and quality problems. In this paper, Internet subsystem with a structure and function has been presented that turns the switching system into the optimized gateway between switching system and Internet. And, this paper developed simulation model and analyzed a performance of inter-processor communication unit which practically functions as an Internet traffic transfer.

• Journal of the Korean Society for information Management
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• v.22 no.1 s.55
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• pp.5-20
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• 2005

This study aims at the fundamental factors needed to make the policy for internet reference service of public records were presented, considering the methods for improvement of internet reference service of national assembly records. For this purpose, reference service theory of recorded informations and examples of foreign congress reference services were analyzed. From the result of analysis, three tasks were proposed as an improvement plan for internet reference services of national assembly records: establishment of access policy, improvement of reference service programs, and activation of communication with users.