使用排列陣列的隱藏通訊系統

Abstract

本論文應用兩個演算法來實作隱藏通訊系統，mapping演算法和embedding演算法。首先，根據排列陣列，mapping演算法利用k-buffer排列器來產生一個排列陣列，此可抵抗敵人的被動攻擊。而mapping演算法則是加入了隨機的元素來加強mapping演算法的安全性。隱藏通訊系統應用這裡個演算法來產生一個排列陣列，並利用了SCTP (Stream Control Transmission Protocol)封包中的傳輸序列號(Transmission Sequence Number)欄位來重新排列所要傳送的資料封包，藉此來傳送所要隱藏的資訊。在隱藏通訊系統中有兩個模型，多媒體模型和檔案模型。根據附信 (Cover letter)的類型和欲隱藏的秘密訊息來分類。當欲傳送的秘密訊息是一個檔案，則選擇多媒體資料型態來傳送，此為多媒體模型；若是要傳送字串為祕密訊息，則利用檔案來作為付信，此為檔案模型。

We design a Steganographic Communication system for secure steganographs comumi-cation. We apply the encoding and decoding algorithms for the permutation arrays to embed (extract) secret into (from) cover letters, respectively. We apply these schemes and use the Transmission Sequence Number field within SCTP packet format to reorder the sequence of packets. Our system can handle two models: one is for multimedia model and the other is for file model. They are classified according to the type of cover letter and secret message. We use multimedia as the cover letter while sending a file as secret message and file as the cover letter while sending a string as the secret message.