An information-theoretic model for steganography

An information-theoretic model for steganography with a passive adversary is proposed. The adversary’s task of distinguishing between an innocent cover message C and a modified message S containing hidden information is interpreted as a hypothesis testing problem. The security of a steganographic system is quantified in terms of the relative entropy (or discrimination) between the distributions of C and S, which yields bounds on the detection capability of any adversary. It is shown that secure steganographic schemes exist in this model provided the covertext distribution satisfies certain conditions. A universal stegosystem is presented in this model that needs no knowledge of the covertext distribution, except that it is generated from independently repeated experiments.
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一種隱秘對手訊息的理論被提出。對手的任務區分合法覆蓋消息C和修改信息包含在隱藏信息之間，被解釋為一種假設檢驗的問題。在安全的隱寫系統的量化計算的區別的分佈在C和S之間，這樣產生的邊界檢測能力上的任何對手。結果表明，存在安全隱寫計劃，在這個模型所提供的覆蓋文件滿足某些條件。一個普遍的隱秘系統提出，在這個模型需要知識的覆蓋文件分佈，除了它是產生獨立的反覆試驗。