16-04-2013, 03:14 PM
Audio Steganography
Audio Steganography.ppt (Size: 272.5 KB / Downloads: 26)
Introduction
Hackers and Identity thieves are constantly coming up with ways to subvert computer & network defenses.
Steganography (literal meaning: covered writing) is one way to accomplish this.
Steganography is the art of passing information in a manner that the very existence of the message is unknown.
Audio Steganography Basics
K. Weeks note that digital steganography is based on the fact that artifacts like bitmaps and audio files contain redundant information.
Compression techniques like JPEG and MP3 eliminate part of the redundancy allowing the file to be compressed.
With DigSteg, you replace some of the redundant information with other data.
The Human Auditory System (HAS) operates over a wide dynamic range of frequencies but it’s fairly poor with respect to its differential range.
Loud sounds tend to mask out software sounds easily. This gives us a clue on possible candidates for DigSteg masking.
Ways to Hide Data in Audio
Low-bit encoding replaces the LSB of information in each sampling point with a coded binary string.
Can encode large amounts of hidden data in a given audio signal at the examples of introducing significant noise at the upper limits.