Topic: F5—A Steganographic Algorithm High Capacity Despite Better Steganalysis
作者: Andreas Westfeld


Abstract:

Many steganographic systems are weak against visual and
statistical attacks. Systems without these weaknesses offer only a rela-
tively small capacity for steganographic messages. The newly developed
algorithm F5 withstands visual and statistical attacks, yet it still of-
fers a large steganographic capacity. F5 implements matrix encoding to
improve the efficiency of embedding. Thus it reduces the number of nec-
essary changes. F5 employs permutative straddling to uniformly spread
out the changes over the whole steganogram.

本篇論文是Andreas Westfeld所撰，發表在2001年的Information Hiding。
由於許多的資訊隱藏系統無法躲過visual attack 和 statistical attack。而那些可以避免被visual attack 和 statistical attack 偵測出的方法又只能嵌入少量的資訊。本篇論文提出了一種嵌入資訊量大而且不會被visual attack 和 statistical attack兩種方法偵測的steganography 作法 – F5。F5的作法使用了metrix encoding這個方法可以在掩護影像裡減少不必要改變情況下提高遷入的資訊量。這個方法將遷入的資訊散佈在整張偽裝影像中。

• Note

• visual attack 和 statistical attack 的差別在於一個由程式自動判別一個靠人眼去判別
• 現在JPEG上的steganalysis 基本上都是算statistical attack,因為在JPEG上的data hiding基本上都是藏在頻率域 而人眼能看到的影像都是空間域