08-01-2013, 02:02 PM
STEGANOGRAPHY IN IMAGES
STEGANOGRAPHY IN IMAGES.ppt (Size: 258.5 KB / Downloads: 97)
STEGANOGRAPHY DEFINED
Greek for “covered writing”
“The art and science of writing hidden messages in such a way that no one apart from the intended recipient even knows that a message has been sent.”
DIGITAL APPROACHES
Today, it often exists within digital formats
It makes use of seemingly innocent cover files such as text, audio, and image files
The embedded message may be anything that can be encoded in binary
REASONS FOR USING DIGITAL IMAGES
It is the most widely used medium being used today
Takes advantage of our limited visual perception of colors
This field is expected to continually grow as computer graphics power also grows
Many programs are available to apply steganography
LSB INSERTION
Replaces least significant bits with the message to be encoded
Most popular technique when dealing with images
Simple, but susceptible to lossy compression and image manipulation
MASKING and FILTERING
Masks secret data over the original data by changing the luminance of particular areas
During masking, it embed the message within significant bits of the cover image
Not susceptible to lossy techniques because image manipulation does not affect the secret message