Steganography and Steganalysis

In addition to embedding and extracting topics, steganography has another topic called "Steganalysis" which analyzes a multimedia file (e.g., image/sound file) and decide it is a stego-file (a file embedded with some secret data) or not.

The aim of steganalysis is to prevent evil internet communications from causing bad effects to the peaceful society. Steganalysis sessions are quite popular in recent international conferences on Information Technology. Some software company has already developed and released a steganalysis software on a commercial basis.

However, we wonder "Is it really possible to develop such software?" In fact they don't say that the developed software can detect any stego files correctly. The program only outputs a message such as "This image file can possibly be embedded with some secret data." The program developer does not guarantee the detection result. As for the detection accuracy, the program user's needs may change case by case, but detection accuracy is higher the better. We will safely say that there is still no steganalysis software that is worth buying it. In the following part of this page, we will show a steganalysis experiment by using a released stego-detection program.

Steganography-software developers do not disclose their embedding methods. Even if someone disclosed the principle, the varieties of the practical implementation are very large, and the details are always kept secret.

Every academic paper on steganalysis first assumes a specific embedding method, and then makes an assertion "As this embedding has this type of weakness, so we can take advantage of that weakness, and this detection method should be very effective." Then it says "The experimental results are here. We found this detection algorithm was very good." This is to say that each paper always stands on an assumption "if the embedding method is known."

Once such paper is publicized, the embedding-program developers can secretly change some programming options to make an easy escape from the weak point. So, it is really hard for the steganalysts to make an effective program even if the embedding method is known in principle. It is safe to say that stegoanalysts can do nothing to find out stego files exactly.

Meanwhile, an embedding-program developer may not be blamed even if he publicly announces "I am using this method", but actually not. This is okay because his lie is allowed by "business secret."

An embedding program developer and a steganalyst are "enemies" against each other. They can't be a same person (same company). But, if someone plays a double role, he is an "arms merchant" who seeks only for money doing anything. His software products are nothing but evil. The embedding-program developers have a great advantage over the steganalysts in their cat-and-mouse race.

We have another page named "Guess Which", where you can enjoy a type of "detective game." You are requested to judge 16 images as "Stego" or "Non-stego."

<Stego-Image detection test by using McAfee software that could be downloaded previously>

We show a stego-detection test by using a McAfee program (performed in the year 2022). 16 sample images tested are shown below.

The images having a * mark to the right of the file size are the stego images embedded with some "secret data" by the "Information Embedding" module of our Qtech Hide & View. So, if you are interested in extracting the secret data, you can do so by the "Information Extracting" module. Some of the Access Keys needed are here. ("Popup block setting" must be "off" with your browser when you download them.) Other keys are ready on request . (When you contact us, go to the formed message sending page.)

Experimental results and our assessment of the detection program are shown in other page.


sample-x1.jpg (242KB)

sample-x2.jpg (161KB) *

sample-x3.jpg (43KB)

sample-x4.jpg (32KB)

sample-y1.png (711KB)

sample-y2.png (504KB) *

sample-y3.png (357KB) *

sample-y4.png (256KB)

sample-z1.png (258KB) *

sample-z2.png (204KB)

sample-z3.bmp (741KB)

sample-z4.bmp (701KB)

sample-z5.jpg (73KB) *

sample-z6.jpg (34KB)

sample-z7.jpg (58KB)

sample-z8.jpg (13KB) *