Steganography/Techniques

Classification Inserting Algorithm Grammar replacement Generate EOF Classification method: Inserting Stego type: Pure Most primitive method, it's about uploading files after ending file. Worked on any file however information carriers are very easy to detect. Pictures are simple a book example of steganography so they could not miss them either. For example, we'll use it in a flickr server. Flickr on the 200 MB limit for a single photo and still does not support RAW files. Let's see how to avoid this inconvenience. You can hide the RAW file inside any single container file "on the lug" by pressing it between or near the end of the original file. For convenience, therefore, they should first create a converted version of the RAW file to the equivalent that supports the service (png, jpg). Later: In Linux: cat obraz-dla-flickr.jpg file-raw.dng> result.jpg in Windows (cmd) copy / b image-for-flickr.jpg + file-raw.dng result.jpg In Mac OS cat image-for-flickr.jpg file-raw.dng >> result.jpg Our final file has hardly changed, except for the size. LSB Classification method: Algorithm Least significant byte This method is probably the easiest way of hiding information in an image and yet it is surprisingly effective. It works by using the least significant bits of each pixel in one image to hide the most significant bits of another. So in a JPEG image for example, the following steps would need to be taken 1. First load up both the host image and the image you need to hide. 2 Next chose the number of bits you wish to hide the secret image in. The more bits used in the host image, the more it deteriorates. Increasing the number of bits used though obviously has a beneficial reaction on the secret image increasing its clarity. 4. Now you have to create a new image by combining the pixels from both images. If you decide for example, to use 4 bits to hide the secret image, there will be four bits left for the host image. (PGM - one byte per pixel, JPEG - one byte each for red, green, blue and one byte for alpha channel in some image types) Host Pixel: 10110001 Secret Pixel: 00111111 New Image Pixel: 10110011 5. To get the original image back you just need to know how many bits were used to store the secret image. You then scan through the host image, pick out the least significant bits according the number used and then use them to create a new image with one change - the bits extracted now become the most significant bits. DCT Discrete cosine transform under construction FFT Fast Fourier transform under construction DSSS Direct-sequence spread spectrum under construction KLT Kanade–Lucas–Tomasi feature tracker under construction