在文字訊息中增加資料隱藏量的新方法

Abstract

隨著網路的普及，社群網站與各種通訊軟體像是Facebook, Twitter, Line, Skype等等，漸漸成為人們日常用來聯絡及溝通的主要管道。因此，文字成為我們最常用來與其他人交換的東西。而當我們在使用這類軟體傳送文字時，如果有些資訊是不希望被第三者輕易看見，例如：帳號，密碼，或重要訊息等，我們可以應用資料隱藏的方式將重要資料隱藏在不易被人察覺的媒介裡。這類的媒介可能是圖片，音樂，或是文字。而本篇將著墨於將資料隱藏於文字之中。然而將資料隱藏於文字中，面臨的最大問題就是可隱藏的資料量及可被隱藏文件的普及性，所以我們提供了一個方法，試著增加一段文字所能隱藏的資料量，且試著讓任何一段簡單的文字，像是往來的書信，新聞報導，或是聊天的內容都能成為隱藏資料的媒介。因此使用了Extended line這個新方法，再搭配White space between words及White space at the end of line這兩個方法來產生含有較大資料量的隱藏文件。實驗的結果顯示，這方法不僅提升了隱藏的資料量，同時也提升了解密時的效率，更重要的是，他可以使用任何簡單文章作為隱藏資料的媒介。

Invention of the Internet and its widespread changes various aspects of human life. Nowadays, people use messenger or social network frequently to communicate with others such as Skype, Line, Facebook, or Twitter, etc. Using the software becomes the most famous method to exchange things with each other. And when we use this type of software to send text, if there is some information that we don’t want to be seen by others, such as account, password, or some important data, we can hide these data in some cover objects. The objects may be pictures, music, or text. And this paper will focus on the information being hidden in the text. However, the biggest issue of hiding data in text is the capacity of hidden data and the types of cover text. Therefore, we provide a method to try to increase the capacity of hidden data and try to make any simple piece of text to be the cover text, such as letters, article of news, or the common message we want to send to our friends. So we use the new approach – Extended Line, and then with White space between words and White space at the end of line to increase the capacity of hidden message in text. The simulation results suggest that the algorithm not only increase the capacity, but also increase the efficiency of decoding. Moreover, it still works on any kind of cover text.