Data Hiding in Audio Files | Project Title with Abstract for Computer Science Students - TamilYoungsters
DATA HIDING IN AUDIO FILES
INTRODUCTION
We are of the belief that the easiest way to keep something from prying
eyes is to place it right in front of the person looking for it and make it
look as innocuous as possible.
Everyone has a taste
for a certain kind of music. Hence, it is more than likely that the person will
have that kind of music on the storage device of his computer. Also, it is
quite common case where people share and transfer different music files to one
another. If one were able to hide the message can be. Also, transfer of this
message can be done quite conveniently without raising any eyebrows.
Our aim is to come up
with a technique of hiding the message in the audio file in such a way, that
there would be no perceivable changes in the
audio file after the message insertion. At the same time, if the message
that is to be hidden were encrypted, the level of security would be raised to
quite a satisfactory level. Now, even if the hidden message were to be
discovered the person trying to get the message would only be able to lay his
hands on the encrypted message with no way of being able to decrypt it.
Data
hiding in audio signals is especially challenging, because the Human Auditory
System (HAS) operates over a wide dynamic range. The HAS perceives over a range
of power greater than one billion to one and a range of frequencies greater
than thousand to one. Sensitivity to additive random noise is also acute.
The perturbations in a
sound file can be detected as low as one part in ten million which is 80dB
below ambient level. However there are some ‘holes’ available. While the has a
large dynamic range, it has a fairly small differential range. As a result,
loud sounds tend to mask out the quieter sounds.
Additionally, the HAS
is unable to perceive absolute phase, only relative phase. Finally there are
some environmental distortions so common as to be ignored by the listener in
most cases.
