一個在欺人耳目的文件中隱藏中文秘密資訊的作法

將秘密的文字資料隱藏在一般文件中的研究（英文叫作Steganography），已經有一段時間，但一般的研究結果，均無法隱藏大量的秘密文字。一九九八年，東海大學林祝興教授等人，提出一個藉由欺人耳目的文件，隱藏秘密文字的作法，稱為「欺人耳目的文件加密方式」(Confused Document Encrypting Scheme, CDES)，結合資料隱藏與密碼學的技術，巧妙地在一般文件中隱藏大量的秘密文字，但若要應用在中文的資料時，則會遭遇一些困難。本篇文章引用林祝興教授等人的基本觀念，利用中文內碼的特性，提出一個新的作法，能夠隱藏大量的中文秘密資料。

關鍵字

資料隱藏；欺人耳目的文件加密方式

並列摘要

In the past years, steganography, the art of hiding information in other meaningful writings, was explored by researchers as a new branch of computer cryptography. Yet, proposed methods cannot hide a large amount of secret information. Lin & Lee proposed a new approach that could hide a large amount of secret information in the confused plain-text document, but their scheme will have some problem for Chinese confused document. In this work, a new scheme is proposed to hide information in Chinese as much as you wish. Our idea, inspired by Lin & Lee's work [Lin & Lee 1998], makes use of the feature of the Big-Five Code, which is the most popular internal code for Chinese systems.