• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.18 no.4
• /
• pp.79-91
• /
• 2008

Modern society as an information society, a lot of information is communicated in on-line. Specially, mobile environment based on radio communication has a characteristic of flexibility compared with wire communication and is developed rapidly. However, the more mobile technology is developed the more security for sensitive information is needed. Therefore, MTM(Mobile Trusted Module) is developed and promoted by TCG(Trusted Computing Group), which is an industry standard body to enhance the security level in the mobile computing environment. MTM, hardware security module for mobile environment, offers user's privacy protection, platform integrity verification, and individual platform attestation. On the other hand, secure migration scheme is required in case secret data or key is transferred from one platform to the other platform. In this paper, we analyze migration schemes which were described in TCG standard and other papers and then propose security maintenance scheme for secret data using USIM(Universal Subscriber Identity Module).

• Journal of Service Research and Studies
• /
• v.2 no.1
• /
• pp.61-68
• /
• 2012

Much technologies building cloud computing environment and supporting sevices on the cloud computing have been developing. Through the environment, accessing new services and sharing knowledge become easy. So far, they have just focused on companies which can support services and people who can use those services. In other words, the environment and models for cloud computing are the most important issue. However, the environment changes rapidly, mobile devices that are connected with each other not only will replace the computing environment based on desktop, but also can create Big data. Therefore, technologies and models are need to follow the trend including mobile based cloud computing environment. In this paper, we explain the cloud computing technologies and trend. Also we address Machine to Machine(M2M) technology and Web of things(WoT) in order to apply those into the cloud computing environment because these two concepts will enhance effectiveness and service reusability in the coming days.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.5
• /
• pp.1143-1152
• /
• 1999

A Mobile computing environment is a new paradigm which provides users with the access to information irrespective of users' location. A transaction scheduling method for the mobile computing environment must be designed so that database consistency is maintained with considering the limited performance of mobile hosts and the narrow bandwidth of a wireless network. The scheduling method using a lock has some problems: the high message overhead between a server and a mobile host for maintaining a lock and the high abort ratio of the mobile transactions owing to violating the serializability when a mobile host uses a cache. So, in this paper, we propose an efficient transaction management method using timestamp to resolve these problems. The proposed method is used in the environment under which a mobile host uses a cache having two versions for each cached data item and a server maintains several versions for each data item. So, even though a mobile transaction is executed during several broadcasting interval, can be committed. As a result, the proposed method can improve the commit ratio of the mobile transactions by maintaining multiversion for each data item and does not require the additional message exchange to schedule transactions by using timestamp.

• Journal of KIISE:Information Networking
• /
• v.28 no.3
• /
• pp.289-296
• /
• 2001

The Election protocol can be used as a building block in many practical problems such as group communication, atomic commit and replicated data management where a protocol coordinator might be useful. The problem has been widely studied in the research community since one reason for this wide interest is that many distributed protocols need an election protocol. However, despite its usefulness, to our knowledge there is no work that has been devoted to this problem in a mobile computing environment. Mobile systems are more prone to failures than conventional distributed system. Solving election in such an environment requires from a set of mobile hosts to choose a mobile host or a fixed host based on the their priority despite failures of both mobile computing and/or fixed hosts. In this paper, we describe a solution to the election problem from mobile computing systems. This solution is based on the Garcia Molina\\`s Bully algorithm.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.9 no.4
• /
• pp.39-45
• /
• 2009

With the rapid growth of recent wireless mobile computing application technology and handheld mobile terminal device development technology, one of the big issue in these fields is to design online games in wireless mobile ad hoc network environment. Online games in mobile computing environment have lots of constraints for developing online games because mobile terminals have many limitations such as low performance of processor, limited memory space, small bandwidth of wireless communication, and confined life of battery power. Therefore, most of mobile games are restrictive in the function of online and multi-play up to date. In this paper, the online MMORPG game, capable of multi-play with many other mobile users using mobile terminals in wireless mobile computing environment, is designed and implemented. Proposed mobile online game uses bluetooth to construct temporary wireless mobile ad hoc network with other mobile clients, and designed to carry out online MMORPG game with these clients. It also supports multi-play among them.

• The Journal of the Korea Contents Association
• /
• v.11 no.9
• /
• pp.85-95
• /
• 2011

Recently, sudden interests of mobile cloud computing as well as conventional internet environment are rapidly increased as cloud computing spread out in our web society. Mobile devices including smart phone are rapidly changing in a wholesale way that covers hardwares, applications, and services. However, the Internet access using mobile device is not quite smooth in this local mobile internet environment which suffers from lack of understanding and observance of Web Standards. Although most of domestic web sites are developed focusing on various functions and eye-catching designs, this should became one of the main factors that make the usability and accessability decrease when accessing web with smart phones or table PCs. Therefore, this paper suggested a web interface that considered usability and accessability under mobile cloud environment and we tried to prove it via usability test. It could be found that there was an improvement of usability of interface of the main page that has been optimized to the mobile device environment suggested from the previous research we present, but this paper aimed to prove a usability improvement of total website as a whole by performing the usability test on the entire website. Selecting a special website optimized for mobile cloud computing, we prove an improvement of usability and accessibility. Therefore, we offer a guideline about user interface design applications to developers or companies who want to construct mobile website.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.10 no.4
• /
• pp.241-255
• /
• 2015

Recent network environment has been rapidly evolved to cloud computing environment based on the development of the Internet technologies. Furthermore there is an increasing demand on mobile cloud computing due to explosive growth of smart devices and wide deployment of LTE-based cellular networks. Thus mobile Desktop-as-a-Service(DaaS) could be a pervasive service for nomadic users. In addition, video streaming traffic is currently more than two-thirds of mobile traffic and ever increasing. All such trends enable that video streaming in mobile DaaS could be an important concern for mobile cloud computing. It should be noted that the performance of the Transmission Control Protocol(TCP) on cloud host servers greatly affects Quality of Service(QoS) of video streams for mobile users. With widely deployed Linux server platforms for cloud computing, in this paper, we conduct an experimental analysis of the twelve Linux TCP variants in mobile DaaS environments. The results of our experiments show that the TCP Illinois outperforms the other TCP variants in terms of wide range of packet loss rate and propagation delay over LTE-based wireless links between cloud servers and mobile devices, even though TCP CUBIC is usually used in default in the current Linux systems.

• ETRI Journal
• /
• v.37 no.2
• /
• pp.348-358
• /
• 2015

Mobile devices have been widespread and become very popular with connectivity to the Internet, and a lot of desktop PC applications are now aggressively ported to them. Unfortunately, mobile devices are often vulnerable to malicious attacks due to their common usage and connectivity to the Internet. Therefore, the demands on the development of mobile security systems increase in accordance with advances in mobile computing. However, it is very hard to run a security program on a mobile device all of the time due the device's limited computational power and battery life. To overcome these problems, we propose a novel mobile security scheme that migrates heavy computations on mobile devices to cloud servers. An efficient data transmission scheme for reducing data traffic between devices and servers over networks is introduced. We have evaluated the proposed scheme with a mobile device in a cloud environment, whereby it achieved a maximum speedup of 13.4 compared to a traditional algorithm.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.4
• /
• pp.1279-1289
• /
• 2000

Recently, research activities for combining portable computer technology and wireless communication technology are in progress to realize mobile computing environment that designed to support mobile hosts in the existing network environments. For PCN environments, the location management strategies are particularly emphasized among various strategies necessary for the mobile computing environment. Location management strategy for PCN environment, which is mostly based on the IS-41 standards brings an issue that additional network traffics are generated to deliver updata messages to home location server whenever a mobile host changes its location server. In this paper, we propose an innovative updata strategy and a search strategy that resolves the problem shown in the IS-41 scheme for HLR/VLR structure of CDMA environments. Also, this paper presents the performance comparison of proposed scheme and scheme used in IS-41 obtained from a simulation. The simulation was conducted based on the number of messages, the rate of database accesses, and the number of hops visited when the location management scheme is executed.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2003.12a
• /
• pp.669-685
• /
• 2003

Nowadays mobile phones and PDAs are part and parcel of our lives. By carrying a portable mobile device with us all the time we are already living in partial Pervasive Computing Environment (PCE) that is waiting to be exploited very soon. One of the advantages of pervasive computing is that it strongly supports the deployment of Location-Based Service(s) (LBSs). In PCE, there would be many competitive service providers (SPs) trying to sell different or similar LBSs to users. In order to reserve a particular service, it becomes very difficult for a low-computing and resource-poor mobile device to handle many such SPs at a time, and to identify and securely communicate with only genuine ones. Our paper establishes a convincing trust model through which secure job delegation is accomplished. Secure Job delegation and cost effective cryptographic techniques largely help in reducing the burden on the mobile device to securely communicate with trusted SPs. Our protocol also provides users privacy protection, replay protection, entity authentication, and message authentication, integrity, and confidentiality. This paper explains our protocol by suggesting one of the LBSs namely“Secure Automated Taxi Calling Service”.