PRESENTED BY:
SUFYAN AHMED KHAN

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STEGO- HUNTER: ATTACKING LSB BASED IMAGE STEGANOGRAPHIC TECHNIQUE
ABSTRACT
Steganography is the process of hiding secret information in a cover image. Our aim is to test a set of images for statistical artifacts due to message embedding in color images using LSB insertion method and to find out, which images out of them are likely to be stego. In a natural uncompressed image (i.e. 24bit BMP) each image is represented by three color channels (Red, Green and Blue), each of the channel is 8 bits wide. The ratio of number of unique colors to the total number of pixels in an image is approximately 1:6 .If any test image is already tampered with message, embedding it further with additional bit streams will not modify the R value significantly. Alternately, if the test image is untampered one, the ratio R decreases significantly when it is further tampered by additional bit streams. Our decision of deciding the image as stego or untampered using the threshold value. After LSB embedding in natural image ,which is equivalent of introducing noise, the randomness of LSB pattern will increase. This will increase the number of close color pairs. We have chosen a deciding factor, that determines the given image as stego image or untampered image. If Deciding factor is greater than 100,then the image you have is an untampered image. Otherwise If Deciding factor is less than 100,then the image you have is an tampered image.
Steganography
– from the Greek word steganos meaning “covered”
– and the Greek word graphie meaning “writing”
 Steganography is the process of hiding of a secret message within an ordinary message and extracting it at its destination.
 Anyone else viewing the message will fail to know it contains hidden/encrypted data.
 Steganography is the process of hiding secret information in a cover image. This process allows user to hide large amount of information with an image are in audio files. In this process, first we have to encrypt the secret data and then hide it in an innocent data. The stego medium is obtained by the addition of cover medium , hidden data and stego key. The cover medium is the file in which we hide our secret data (hidden data).The cover medium is typically an image file or audio files. The stego medium is also the same type of file in the cover medium. The stego image should not contain any easily detectable information by the human eye.
HISTORY:
 Greek history – warning of invasion by scrawling it on the wood underneath a wax tablet. To casual observers, the tablet appeared blank.
 Both Axis and Allied spies during World War II used such measures as invisible inks -- using milk, fruit juice or urine which darken when heated.
 Invisible Ink is also a form of steganography.
 Steganography (a rough Greek translation of the term Steganography is secret writing) has been used in various forms for 2500 years. It has found use in variously in military, diplomatic, personal and intellectual property applications. Briefly stated, steganography is the term applied to any number of processes that will hide a message within an object, where the hidden message will not be apparent to an observer. This paper will explore steganography from its earliest instances through potential future application.
 The first recorded uses of steganography can be traced back to 440 BC when Herodotus mentions two examples of steganography in The Histories of Herodotus.[2] Demaratus sent a warning about a forthcoming attack to Greece by writing it directly on the wooden backing of a wax tablet before applying its beeswax surface. Wax tablets were in common use then as reusable writing surfaces, sometimes used for shorthand. Another ancient example is that of Histiaeus, who shaved the head of his most trusted slave and tattooed a message on it. After his hair had grown the message was hidden. The purpose was to instigate a revolt against the Persians.