• Journal of KIISE:Computer Systems and Theory
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• v.34 no.11
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• pp.581-588
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• 2007

In Digital Right Management, symmetric cipher is used for content encryption to reduce encryption cost, AES, advanced encryption standard is usually used to multimedia encryption under desktop environment because of its reasonable security level and computation cost. But mobile handheld device often uses slow speed processor and operates under battery-powered environment. Therefore it requires low computation cost and low energy consumption. This paper proposes new stream cipher scheme which combines pseudo random number generator(PRNG) and dynamically generated permutations. Proposed scheme activates PRNG and generates original key streams. Then it generates extended key streams by applying permutation to original sequence. These extended key streams are XORed with plaintext and generate ciphertext. Proposed scheme reduces the usage of PRNG. Therefore this scheme is fast and consumes less energy in comparison with normal stream cipher. Especially, this scheme shows great speed up (almost 2 times) than normal stream cipher scheme in random access.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2207-2216
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• 2012

Recently, wireless Internet environment with mobile phones and wireless sensor networks with severe resource restrictions have been actively studied. Moreover, an overall security issues are essential to build a reliable and secure sensor network. One of secure solution is to develop a fast cryptographic algorithm for data encryption. Therefore, we propose a 128-bit stream cipher, AA128 which has efficient implementation of software and hardware and is suitable for real-time applications such as wireless Internet environment with mobile phones, wireless sensor networks and Digital Right Management (DRM). AA128 is stream cipher which consists of 278-bit ASR and non-linear transformation. Non-linear transformation consists of Confusion Function, Nonlinear transformation(SF0 ~ SF3) and Whitening. We show that the proposed stream cipher AA128 is faster than AES and Salsa20, and it satisfies the appropriate security requirements. Our hardware simulation result indicates that the proposed cipher algorithm can satisfy the speed requirements of real-time processing applications.

• Convergence Security Journal
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• v.7 no.2
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• pp.135-143
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• 2007

This study proposes a DRM system for VOD streaming services in a mobile environment. The proposed system consists of DRM client manager (Consumer), in which core components for client services are independently constructed to be used in a mobile environment, and DRM server, which provides DRM services. Consumer independently exists in the client to maximize efficiency and processing capacity in such a mobile environment, and consists of license service, content service, access service, and tracking service. DRM server consists of streaming server for VOD streaming, distributor, license server, and provider. The proposed system has an architecture suitable for a mobile environment that is difficult to process in the existing DRM system and can solves the super-distribution using license manager in client manager.

• Information Systems Review
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• v.14 no.1
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• pp.67-84
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• 2012

Recent increases in uncertainty and speed of market change are driving the adoption of new intelligent mobile office systems. Organizational information systems paradigm suggests that a right match between organizational characteristics and the use of technology is critical in producing desired results. Following such perspective this study developed the mobile office system case of Seoul Metropolitan Railway Transit(SMRT) in Korea. SMRT developed the mobile task-supporting environment that help the management of subway lines real-time without the restriction of time and space. They named the system as ST&F(SMRT Talk and Flash). They decided to develop the application systems in-houses they did not want to be overly dependent on external services in future changes and developments of the system. The new practice reduced the time for moving back and forth to 10% of their working time from previous 20%. The time used for paper works and administration chore also reduce to 10% of their working time from previous 30% on the average. The employees could use 80% of their time to concentrate on the completion of assigned task. The effects of this improvement resulted in the heightened efficiency of the use of human resources and the heightened level of railway safety. The case of SMRT shows that the mobile office system can be applied and extended to various business areas such as facility management and maintenance beyond such typical uses as sales and marketing support. Also, The result of case study will be a useful guideline on the construction and using of mobile office system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.225-228
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• 2004

Digital contents is used already in near place with us. Contents of MPEG-4 standard is used to process multimedia data in field of communication, computer, broadcasting mobile etc. However, absence of copyright management and protection system and interoperability problem of right system between each corporation happened. Because MPEG establish IPMP(Intellectual Property Management and Protection) system standard in agreement with MPEG-4 system standard, proposed cooperation method to manage and protect copyright. Accordingly, in this paper, put in copyright of authorized contents management and protection extension system implementation adding MPEG-4 IPMP system like plug-in into existing MPEG-4 authorizing tool. Therefore, author edits IPMP information to protect contents or object, and process the information in system and authorize MPEG-4 digital contents that have management and protection sign according to IPMP standard. This system designed and implemented to divided into IPMP information save processor, IPMP information creation processor, media IPPM processor, XMT-A to MP4 converter IPMP extension.

• ETRI Journal
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• v.32 no.5
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• pp.665-675
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• 2010

Recent research on mobile Internet protocol television and digital right management (DRM) interconnections has focused on multimedia technologies designed to enhance content scalability and adaptive content distribution. However, due to the architectural and scalable limitations, recent systems are not flexible and securable with respect to their adaptive content distribution and protective policy management. Therefore, we propose a content protective multi-agent platform that provides secure multimedia services, correlation management, pattern-based management, and multi-source multi-use (MsMu)-based services. Our architecture, supported by DRM, lets us create a rich set of MsMu-based content protection and seamless multimedia services through the extension of one source multi-use (OsMu)-based content services. We have verified our platform, which provides scalable and securable services with a 17% lower service response time by using a testbed.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.7
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• pp.71-79
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• 2012

Propose stream cipher Canon that need in Wireless sensor network construction that can secure confidentiality and integrity. Create Canon 128 bits streams key by 128 bits secret key and 128 bits IV, and makes 128 bits cipher text through whitening processing with produced streams key and 128 bits plaintext together. Canon for easy hardware implementation and software running fast algorithm consists only of simple logic operations. In particular, because it does not use S-boxes for non-linear operations, hardware implementation is very easy. Proposed stream cipher Canon shows fast speed test results performed better than AES, Salsa20, and gate number is small than Trivium. Canon purpose of the physical environment is very limited applications, mobile phones, wireless Internet environment, DRM (Digital Right Management), wireless sensor networks, RFID, and use software and hardware implementation easy 128 bits stream ciphers.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.325-327
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• 2004

무선 인터넷의 보급과 맞물려 모바일 컴퓨팅 환경이 구축됨에 따라 PDA와 같은 소형의 모바일 장비에 최적화된 디지털 컨텐츠의 제작 및 배포가 활발해지고 있으며 불법적인 디지털 컨텐츠의 이용 또한 이에 비례하고 있다. 그러나 유선환경에 기반 한 기존의 DRM 시스템은 상대적으로 속도와 표현능력이 떨어지는 모바일 환경에는 적합하지 않으며 현재 연구.개발된 모바일 환경에서의 DRM 시스템은 음악, 문서, 이미지에 국한되어 있어 동영상과 암호화와 같은 높은 연산 능력을 요구하는 부분의 개발과 연구는 초기 단계에 머물러 있다. 본 논문에서는 모바일 환경에 적합하도록 적은 연산 능력으로도 기존의 DRM 시스템에 준하는 보안 강도를 갖을 수 있도록 동영상의 부분 암호화 방식과 공유키 풀 기반의 인증 방법을 사용하는 DRM 시스템을 설계ㆍ제안한다.

• Information Systems Review
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• v.8 no.2
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• pp.29-49
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• 2006

The introduction of the Digital Economy has formed a new market producing and trading information. Depending on the current contexts, each user evaluates identical information differently. It is difficult, even though important, to create and deliver the information customized to individual users by using some factors as time, location, and their personal characteristics. Information value, therefore, could be influenced by the capability of information systems to delivery useful information based on individual contexts to the right user immediately at the right time. From this point of view, we argue mobile systems which are able to be aware of individual contexts and deliver contextual information in real time can improve information value easily than other systems can. This research presents the results of an empirical test about antecedents to mobile advertising value. Though context relevance doesn't influence directly mobile advertising value, it plays an important role enhancing information usefulness which has great influence on mobile advertising value. Moreover, to supply information connected with users' context overcomes the effect of irritation. Lastly, entertainment can improve mobile advertising value as satisfying user's hedonic desire beyond the information source supporting decision making.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.6B
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• pp.954-961
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• 2010

Stream cipher was worse than block cipher in terms of security, but faster in execution speed as an advantage. However, since so far there have been many algorithm researches about the execution speed of block cipher, these days, there is almost no difference between them in the execution speed of AES. Therefore an secure and fast stream cipher development is urgently needed. In this paper, we propose a 32bit output fast stream cipher, AA32, which is composed of ASR(Arithmetic Shifter Register) and simple logical operation. Proposed algorithm is a cipher algorithm which has been designed to be implemented by software easily. AA32 supports 128bit key and executes operations by word and byte unit. As Linear Feedback Sequencer, ASR 151bit is applied to AA32 and the reduction function is a very simple structure stream cipher, which consists of two major parts, using simple logical operations, instead of S-Box for a non-linear operation. The proposed stream cipher AA32 shows the result that it is faster than SSC2 and Salsa20 and satisfied with the security required for these days. Proposed cipher algorithm is a fast stream cipher algorithm which can be used in the field which requires wireless internet environment such as mobile phone system and real-time processing such as DRM(Digital Right Management) and limited computational environments such as WSN(Wireless Sensor Network).