Various digital watermarking techniques have been proposed in recent years as the methods to protect the copyright of multimedia data. However, as pointed out by the IBM research group, the rightful ownership problem has not been properly solved. Currently, there are two proposals to solve the ownership problem. Unfortunately, one proposal lacks a formal proof and the other can be easily defeated. In this paper, we present watermarking methods which will be successful in resolving rightful ownership of watermarked MPEG video. By introducing speci c requirements in the watermark construction, the proposed scheme is proved to be non-invertible. We show the invertibility of those schemes which do not use the original in its veri cation, discuss in depth various issues of the watermark construction requirements, extent the basic idea to create a non-invertible scheme for image, and discuss the usage of di erent non-invertible schemes. Keyword: Watermarking of MPEG video, IBM attack on wat...