Disappeared Cryptography, Second Edition explains how to take words, sounds, or images and hide them in digital data so that they look like other words, sounds, or images. Conversations can be submerged in the flow of information through the internet so no one can know whether any conversation at all. Full revision of the bestselling first edition describes a number of different techniques to hide information. These include encryption, making data understandable; steganography, embedding information into video, audio, or graphics files, watermarking, hiding data in image noise or sound files, mimicry, "dressing up" data and makes it look like other data, and more. Each chapter is divided into several parts, first giving an introduction and high-level summary for those who wish to understand the concepts without wading through technical explanations, and then presenting greater detail for those who wish to write their own programs. Each chapter is divided into several parts, first giving an introduction and high-level summary for those who wish to understand the concepts without wading technical details, and then a set of introductory details, for those who wish to write their own programs.