中英文秘密文件的分享與隱藏

1998年Lin et al.提出了一個新的文件保護機制，利用有具體內容的文件來傳送秘密訊息，其後亦陸續有學者針對此方法加以延伸與改進，但是這套文件保護的方法仍有許多待改進之處。本研究的目的便是針對此套文件保護的機制，提出一個改進的方法，將秘密文件位置索引表改成差值表，並且增加機密分享的機制。本研究與其它研究比較，具有以下幾項優點：(1)本研究可以取用任何文字做為欺敵訊息；(2)不同的秘密訊息可以共用相同的欺敵訊息；(3)本研究可以處理中英文夾雜的訊息；(4)本研究可以防止部份差值表遺失以效無法還原秘密的情況；(5)本研究可以達到機密控管，降低洩密的風險；(6)最後所傳送出去的檔案皆是有具體內容的文件，不容易引人懷疑。

關鍵字

文件保護機制；秘密分享；資訊隱藏

並列摘要

In 1998, Lin & Lee proposed a new document protection scheme which utilized a meaningful cheating document to protect the secret document from hackers. Afterward some researchers extended and improved their scheme. However, there are still lots of spaces for improvement. The purpose of our study is aimed at reforming their method via recording the code differences instead of recording the code indices, coupled with a secret sharing scheme. Compared with other studies, ours have the following advantages: 1. we can utilize any text as a cheating message; 2. different secrets can use the same cheating message in common; 3. we can handle a bilingual secret document easily without any special treatment; 4. we can recover the code difference table even if one of the share messages is lost; 5. we can decrease the risk of blabbing out the secret; 6. all the files delivered to the receivers are meaningful without giving rise to attentions of hackers.