Steganography is the art and science of hiding information in inconspicuous cover data so that even the existence of a secret message is kept confidential, and steganalysis is the task of detecting secret messages in covers. This research monograph focuses on the role of cover signals, the distinguishing feature that requires us to treat steganography and steganalysis differently from other secrecy techniques. The main theoretical contribution of the book is a proposal to structure approaches to provably secure steganography according to their implied assumptions on the limits of the adversary and on the nature of covers.

隐写术是一门将信息隐藏在不显眼的封面数据中的艺术和科学，这样即使是秘密信息的存在也会被保密，而隐写分析则是检测封面中的秘密信息的任务。本研究专著侧重于覆盖信号的作用，这一特点要求我们以不同于其他保密技术的方式对待隐写术和隐写分析。这本书的主要理论贡献是，根据对手的限制和封面的性质的隐含假设，提出了构造可证明安全的隐写术的方法。