-
This research work takes place in the field of information hiding, considerably developed
these last two decades. The proposed method for
steganography considers digital images as covers.
Let us recall that, in this LSBR category, a subset of all the LSBs of the cover image is modified
with a secret bit stream depending on: a secret key, the cover, and the message to embed.
In this well studied steganographic approach,
-pixels with even values (resp. odd values) are never decreased (resp. increased),
+if we consider that a LSB is the last bit of each pixel value,
+pixels with an even value (resp. an odd value)
+are never decreased (resp. increased),
thus such schemes may break the
structural symmetry of the host images.
And these structural alterations can be detected by
the better the approach is said to be.
Contrarily, we argue that some images should not be taken as a cover because of the nature of their signal.
Consider for instance a uniformly black image: a very tiny modification of its pixels can be easily detectable.
-The approach we propose is thus to provide a self adaptive algorithm with a high payload, which depends on the
-cover signal.
-
-Additionally, in the steganographic context, the data hiding procedure is often required
-to be a reversible one. We thus need to be able to compute the same edge detection pixels set for the cover and the stego image. For this, we propose to apply the edge detection algorithm not on all the bits of the image, but to exclude the LSBs which are modified.
-% Finally, even if the steganalysis discipline
-% has done great leaps forward these last years, it is currently impossible to prove rigorously
+The approach we propose is thus to provide a self adaptive algorithm with a high payload, which depends on the cover signal.
+% Message extraction is achieved by computing the same
+% edge detection pixels set for the cover and the stego image.
+% The edge detection algorithm is thus not applied on all the bits of the image,
+% but to exclude the LSBs which are modified.
+
+Finally, even if the steganalysis discipline
+ has done great leaps forward these last years, it is currently impossible to prove rigorously
that a given hidden message cannot be recovered by an attacker.
This is why we add to our scheme a reasonable
message encryption stage, to be certain that,
