Steganography, An Ulterior, And Lesser Known Approach For Private Communication

1461 Words Dec 12th, 2015 6 Pages
Steganography is an ulterior, and lesser-known approach to private communication. Steganographic applications work by taking in three things: a cover work; this could be a picture, an audio file, a video file, etc., a message to be embedded, and a stego key; we don’t always use one but if we do it is much like an encryption key. Steganography applications will then embed the message into the cover work. This is most commonly performed using a method known as LSB embedding, which I will explain in detail.

LSB embedding involves taking the gray scale values of certain pixels, and making sure the LSB, or least significant bit is set to the bit value needed. If we have a gray scale value of 51, or 00110011, and we need to have a 0 embedded at this pixel value, the application will simply change the gray scale value to 50, or 00110010. If the grey scale value already ended in a 0 we would leave it as is. Within LSB embedding are three options for how the pattern of pixels are chosen. The first method; which has the lowest form of security, is sequential. This method embeds the pixels in a sequential manner, for example: left to right, top to bottom. The second method is pseudo (random). This method works exactly as it sounds and simply embeds based on a random pattern, which can be initialized by the stego key provided. The third, and most secure, method is adaptive. Adaptive works intelligently, by first analyzing the cover work and identifying locations where statistical…
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