Abstrakt:
Although steganography has been known since the 15th century, its bloom as a scientific branch came as late as the second half of the 20th century. Contemporary information technology allows for use of steganographic principles to place hidden content in both visual and audio media. The article covers application of mathematical methods and software engineering methods for hiding pictures within pictures, and their subsequent recovery. The techniques described and applied for concealing pictures are: a) LSB modulation, b) Y-channel addition, c) pixel-set addition, d) frequency method and e) addition for jpg compression. Apart from introducing the methods and describing them, a software solution allowing for demonstration is also described. The next part of the article covers the problematic of concealing audio content, with the help of the following methods: a) LSB modulation, b) parity encoding, c) phase shift, d) tone addition.
