Digital Watermarking And Its Protocols' Application In Copyrights Protection

The recent rapid growth of network multimedia systems has increased the need for the protection of digital media. Now ,there are three techniques to protect multimedia contents:digital watermarking techinique(such as watermarking algorithms and watermarking protocols) cryptographic techniques (such as encrypted algorithms, digital signature, Hash functions, authentication systems) and fingerprint identification techniques .Among these methods, digital watermarking techniques are more effective, especially when we construct a secure digital watermarking architecture with digital watermarking techniques and its protocols.On the basis of some theses of digital watermarking and its protocols home and abroad,I introduced the history and algorithms of digital watermarking techniques, and the attacks on some kind of algorithms; from the historic triangle,summarized the process of digital watermarking and its protocols,analysize the earliest protocol,find two problems it hasn't solved:one is the co-attack problem(the buyer and the TTP and the seller and the TTP), the other is the protocol of redistribution. At last, based on the digital watermarking and its protocol,we proposed some ideas about the secure digital watermarking architecture.The main creative achievements are as following:1.Analysize the disadvantages of recent watermarking algorithms, introduce the attack methods of recent watermaking algorithms in details.2.Summarize the problems of recent digital watermarking protocols, analysize the existing digital watermarking protocols,especially in its structure,the existing digital watermarking protocols generally includes 4 sub protocols: watermark generation protocol, watermark insertion protocol,copyright violator identification protocol and dispute resolution protocol.3.Based on the existing digital watermarking protocols and some kind of theses,to solve two main problems--co-attack problems and redistribution problems, I have introduced two digital watermarking protocols:one is proposed by share-secrets and homomorphic public key cryptosystem ,named digital watermarking protocol without the trusted third party; the other is based on the S.C.Cheung's buyer-reseller watermarking protocol, named redistribution digital watermarking protocol.