Abstract: One of the expected application areas for the practical use of the watermarking technology is for protecting contents from illegal distribution and/or copying, such as for DVD copy protection. In such application areas, the watermarked contents should be robust with regards to various kinds of post-processing, such as digital-to-analog or analog-to-digital (D/A,A/D) conversion, MPEG compression, and VHS recording. This paper introduces a watermark embedding method that maximizes the strength of the detected watermark signal, an embedding method robust against MPEG compression, and an embedding method robust against VHS recording, without affecting the fidelity of the watermarked contents.