Аннотация:
The Least Significant Bit (LSB) method is one of the most widespread and demanded
steganographic methods nowadays. Detection and decoding the hidden information, embedded
in a container using the LSB, is a challenging task, in particular, in conditions of low capacity
of the hidden communication channel. The existing steganalysis algorithms developed to detect
the LSB, as a rule, solve the main problem of steganalysis - the detection of a hidden
communication channel. However, the problem of the additional information recovery remains
unfulfilled. The important step in solving this problem is the evaluation of the hidden
(steganographic) channel capacity. In the current work, a digital image is used as container. All
the results obtained can also be applied to digital video, which is considered as a sequence of
frames. The aim of the work is to get estimates for the value of the capacity of the hidden
communication channel, formed by the LSB method. To achieve the aim of the work the
following studies carried out: performed additional in-depth investigation of properties of the
normalized gap of the maximum singular value of non-intersecting image blocks, obtained by
standard splitting; studied properties of a discrete function y(QF), that determines the number of
image blocks in which the normalized gap of maximum singular value increases when the image
is re-saved to lossy format with quality factor QF. As a result of the research, the estimates of
the value of the capacity of the hidden communication channel, created using the LSB method
and based on a container in a lossy format, were obtained.
