Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Hierarchical Spread Spectrum Fingerprinting Scheme Based on the CDMA Technique Minoru Kuribayashi (EURASIP Member) | Hindawi Publishing Corporation EURASIP Journal on Information Security Volume 2011 Article ID 502782 16 pages doi 2011 502782 Research Article Hierarchical Spread Spectrum Fingerprinting Scheme Based on the CDMA Technique Minoru Kuribayashi EURASIP Member Graduate School of Engineering Kobe University 1-1 Rokkodai Nada Kobe Hyogo 657-8501 Japan Correspondence should be addressed to Minoru Kuribayashi kminoru@ Received 10 March 2010 Revised 15 December 2010 Accepted 20 January 2011 Academic Editor Jeffrey A. Bloom Copyright 2011 Minoru Kuribayashi. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Digital fingerprinting is a method to insert user s own ID into digital contents in order to identify illegal users who distribute unauthorized copies. One of the serious problems in a fingerprinting system is the collusion attack such that several users combine their copies of the same content to modify delete the embedded fingerprints. In this paper we propose a collusion-resistant fingerprinting scheme based on the CDMA technique. Our fingerprint sequences are orthogonal sequences of DCT basic vectors modulated by PN sequence. In order to increase the number of users a hierarchical structure is produced by assigning a pair of the fingerprint sequences to a user. Under the assumption that the frequency components of detected sequences modulated by PN sequence follow Gaussian distribution the design of thresholds and the weighting of parameters are studied to improve the performance. The robustness against collusion attack and the computational costs required for the detection are estimated in our simulation. 1. Introduction Accompanying technology advancement multimedia content audio image video etc. has become easily available and accessible. However such an advantage also causes a serious .
