In recent years, the applications about multimedia have been developed rapidly. Digital media brings about conveniences to the people, because it is easy to be processed. At the same time, it enables the illegal attackers to attack the works. For the protection of data there has been growing interest in developing effective techniques to discourage the unauthorized duplication of digital data. Digital watermarking is the process of embedding information into a digital signal in a way that is difficult to remove. The fragile and semi fragile watermarking techniques have some serious disadvantages like increased use of resources, larger area requirements, and high power consumption. In order to overcome this, robust watermarking technique is proposed. Robustness can be defined as resilience for a watermark to remain unaffected even when digital content is passed through various processes and attacks. Invisible robust watermarking is the most accurate method. Embed a watermark containing key information such as authentication or copyright codes.

1. P Karthigaikumar, K Baskaran,” An ASIC implementation of a low power invisible robust watermarking processor”in proceedings of journal of system architecture,2010.
2. Saraju P mohanty ,N Ranganathan,”VLSI architecture and chip for combined invisible robust and fragile watermarking”, in proceedings of the IEEE workshop on signal processing system,19 June 2007.
3. A Mohamed Zuhair ,A Mohamed Yousef ,”FPGA based image securityauthentication in digital camera using invisible watermarking technique” International journal of engineering science and technology vol .2(6), ,1745-1751, 2010.
4. DR .M A Dorairangaswamy,”A noval invisible and blind watermarking scheme for copyright protection of digital images” International journal of computer science and network security vol9 No.4 ,April 2009.
5. Christian Rey , Jean-Luc Dugelay,” A surey of watermarking algorithams for image authentication”, EURASIP Journal on applied signal processing, 6, 613-621, 2002
6. Afrin Zahra Husaini and M Nizamuddin,Challenges and approach for a robust image water marking algorithm, International journal of electronics engineering 2(1), pp 229-233, 2010.
7. Raja’ S Alomari and Ahmed Al Jaber, “A Fragile watermarking Algorithm for content authentication “International journal of computing and information science vol 2.No. 1 April 2004.
8. R. Schyndel, A. Tirkel, and C. Osborne, “A digital watermark,” in IEEE,Proc. Int. Conf. Image Processing, vol. 2, pp. 86–90, 1994.
9. S. P. Mohanty, R. Kumara C., and S. Nayak, “FPGA Based Implementation of an Invisible-Robust Image Watermarking Encoder,” Lecture Notes in Computer Science (LNCS), CIT 2004, Springer-Verlag, Vol. 3356, pp. 344-353, 2004.
10. S. P. Mohanty, N. Ranganathan, and R. K. Namballa, “VLSI Implementation of Invisible Digital Watermarking Algorithms Towards the Development of a Secure JPEG Encoder,” in Proceedings of the IEEE Workshop on Signal Processing Systems (SIPS), pp. 183-188, 2003.
11. J. R. Kim, and Y. S. Moon, “A robust wavelet-based digital watermarking using level-adaptive thresholding,” in IEEE Proc. Int. Conf. Image Processing, Japan, pp. 226-230,1999.

Digital watermarking DWT invisible watermarking copyright protection