Research Of Anti-collusion Fingerprinting Embedding And Traitor Tracing Technology

With the development of the E-Business and Internet, Multimedia works and software products in digital formats spreading in networks have become a mainstream. When it bring us convenience,it also has brought many negative effects, such as unauthorized copying, information rectification etc. The traditional encryption will lost the defense after decrypting. So, digital watermarking system came into being. To some extent, the digital watermarking system can solve this problem partly. But the ordinary watermark has its own limitations. Then the digital fingerprint is introduced. Digital fingerprinting protects copyrights by embed different fingerprint code into digital works. When we find pirated works, the original users of pirated works can be confirmed by extracting the fingerprint.Digital fingerprint range over fingerprint coding, fingerprint embedding, fingerprint extracting, fingerprint tracing etc. The classification of the fingerprint coding scheme are discussed. By comparatively analyzing four commonly used fingerprint encoding methods, it was found that I code generate easily and BIBD codes can reduce the encoding length effectively. Combined with the advantages of these two codes, a new fingerprint generating method which mixed BIBD code with I code is proposed. This method encodes easily and can reduce code length largely, at the same time it also can resist "Logical and" and "logical or" collusion-attack, and track the collusion-users effectively.To make full use of the multi-resolution characteristics of DWT, decorrelation ability and the energy-compression capabilities of DCT, the method which combined DCT with DWT to embed and extract fingerprinting is used. So the encryption-object has good imperceptible capability and robustness.To verify the feasibility and effectiveness of the algorithm, a prototype-system of digital fingerprints is designed and implemented. To process the original fingerprint-code with chaotic-sequence-modulation before publishing, it can effectively prevent the publisher framing users. Experiments show that the prototype-system of digital fingerprint has good robustness and invisibility, and resistance to both collusion-attack.