Digital Copyright Protection describes how to defend copyrighted material in an age when digital technology makes copying cheap and easy. In this highly acclaimed book, Wayner has composed a thorough guide to watching, tracing, and locking up copyrighted material, making this book a necessity for anyone planning on controlling their work in the modern digital era. This encompassing guide to defending digital copyright includes detailed discussions on network-based key systems, compression-based tagging, and tamper-resistant tagging. Discussions also address key-based systems that lock up information until the right key is entered, embedding information in the images, music, or text. The techniques discussed focus on tagging documents with messages that indicate the rightful owner of the document and the copyright holder. These tags can be inserted in text files, images, or sound files. The book also explores key-based systems for keeping data secure until someone purchases it. These keys can be distributed by phone, stores, or the Internet.