The Combined Application Of The Watermarking Algorithm Based On Singular Value Decomposition And RSA Public-Key Cryptographic

With the development of the multimedia and the network technology, the application of the digital product is more and more wide. The security of the digital information becomes the concern in people' s life. Especially, the copyright protection of digital product is more important and urgent. Of all the solution to the copyright protection, the watermarking technology is more effective one.Therefore; the study of this technology becomes a focus in the academic world.In this dissertation, we study still image digital watermarking, proposed one kind the digital watermarking algorithm which combines based on the matrix singular value decomposition and the RSA public key system, the main works are as follows:(1) To research the nature of SVD (singular value decomposition) as well as the singular value decomposition on image, summarize and analysis the existing watermarking algorithm which performs decomposition based on the SVD.(2) To propose one kind algorithm which combines the watermarking based on the SVD transformation to the original image and the scrambling algorithm which applies pseudo-random sequence scrambling to the watermarking image, and implements blind-extraction to realize watermark information from inserted image by applying the calculation of the Euclid norm. In this algorithm, A key sequence is generated by applying pseudo-random sequence scrambling to the blocking partitioned watermark image, which is used to encrypt the the insert and extract procedure of watermarking.(3) To combine this kind watermarking algorithm based on the SVD and the public key cryptographic system, apply the RSA public key cryptographic to protect the transmission of the key. Thus the digital watermarking and the digital visa can be combined in together very well.(4) To describe the application mode of this algorithm in practical networking application and make analysis the effect of this algorithm on the field of digital image product copyright protection.