Hard-Drive Steganography through Fragmentation
Khan and his colleagues have written software that ensures clusters of a file, rather than being positioned at the whim of the disc drive controller chip, as is usually the case, are positioned according to a code. All the person at the other end needs to know is which file’s cluster positions have been encoded.
The code depends on whether sequential clusters in a file are situated adjacent to each other on the hard disc or not. If they are adjacent, this corresponds to a binary 1 in the secret message.