Analysis of LSB based image steganography techniques

But practical implementation of the definition is not feasible, so pragmatic approach would be to make the algorithm as strong as possible. Steganography is most widely formulated in terms of the prisoner’s problem where Alice and Bob are two inmates who wish to communicate in order to hatch an escape plan. However, all communication between them is examined by the warden, Wendy, who will put them in solitary confinement at the slightest suspicion of trouble. Specifically, in the general model for steganography, we have Alice wishing to send a secret message M to Bob. In order to do so she ”embeds” M into a cover-object C, to obtain the stego-object S. The stego-object S is then sent through a public channel. The warden Wendy who is free to examine all messages exchanged between Alice and Bob can be passive or active. A passive warden simply examines the message and tries to determine if it potentially contains a hidden message. If it appears that it does, then she takes appropriate action else she lets the message through without alteration. An active warden on the other hand can alter messages deliberately, even though she does not see any trace of a hidden message, in order to foil any secret communication that can nevertheless be occurring between Alice and Bob.