This book constitutes the thoroughly refereed postproceedings of the Second International Workshop on Digital Watermarking, IWDW 2003, held in Seoul, Korea, in October 2004.The 44 revised full papers presented together with 4 invited articles were carefully selected during two rounds of reviewing and improvement from more than 90 submissions. The papers address all current aspects of digital watermarking, in particular theoretical modeling, robustness, capacity, imperceptibility and the human perceptual system, security and attacks, watermarking systems and implementations, and integration of digital watermarking in digital rights management.