• Journal of information and communication convergence engineering
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• v.5 no.3
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• pp.254-258
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• 2007

Recently, ubiquitous computing in being actively researched and one of the main technology in ubiquitous computing environments is recognized as RFID system. The RFID system has much benefits but simultaneously has some problems such as user's privacy violation. In this paper, in order to improve the survivability of its nodes, it should build available simulation surrounding sensor nodes. Also, In the proposed cryptosystems we use a new hash function for user authentication and a stream cipher based on LFSR(Linear Feedback Shift Register) for message encryption and decryption. Moreover, each algorithm is programmed with C language and simulated on IBM-PC system and we analyze the randomness properties of the proposed algorithms by using statistical tests.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.790-795
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• 2007

최근 유비쿼터스 컴퓨팅에 대한 연구가 활발히 진행되고 있으며 유비쿼터스 컴퓨팅의 실현을 위한 핵심기술로서 RFID 시스템에 대한 연구가 활발히 진행되고 있다. 유비쿼터스 환경에서 RFID 시스템이 사용자의 편리함을 가져다 주는 장점이 있는 반면, 이로 인해 사용자의 프라이버시가 침해 당할 수 있는 문제점 또한 가지고 있다. 본 논문에서 사용자 인증 알고리즘은 새로운 해쉬 함수를 사용하고 그리고 메시지 암호화를 위한 스트림 암호기는 LFSR(Linear Feedback Shift Register)을 사용한다.

• The Journal of the Korea Contents Association
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• v.5 no.1
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• pp.157-167
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• 2005

In this paper, we propose a new phantom protection method for multi-dimensional index structures. The proposed method uses a hybrid approach of predicate locking and granular locking mechanisms. The proposed mechanism is independent of the types of multi-dimensional index structures, i.e., it can be applied to all types of index structures such as tree-based, file-based and hash-based index structures. Also, it achieves low development cost and high concurrency with low lock overhead. It is shown through various experiments that the proposed method outperforms existing phantom protection methods for multi-dimensional index structures.