I am new very new to networking concepts I do not have any idea about network steganography. Can anyone please explain what it is. what is its advantages and disadvantages?
Steganography is the art of hiding information in other things, often related to images.
In the case of networks, you can play for example with TCP headers to send a hidden message. Here you have a paper -> http://gray-world.net/es/papers/ih05coverttcp.pdf
As long as two points in timespace is connected by a communication medium, information can be smuggled. Instead of hiding information by modifying the payload, network steganography modifies parts not recognized as payload, eg:
- permutation of wave-shape data
- permutation of fragments data
- permutation of optional tag data
- permutation of header data
- permutation of invalid/malformed frames and packets
It can work with literally any protocol from "layer 1" to "layer 7".
Network steganography relies on the fact that in the present market it's nontrivially more expensive to log and analyze communications that are not recognized as payload data.
Another form of network steganography smuggles information by modifying patterns of time instead of that of space. (Instead of sending the signed message 101110110 using bits, they can be sent by varying the time between bits. (End users may want to vary the time between messages instead. (Eg a 1-sec gap to mean bit 1 and a 10-sec gap to mean bit 0.) (The availability of this medium however depends on the intermediaries' traits. (Eg a caching medium may decide to forward messages only once per 5 minutes, or in a random order.))))
Detecting network steganography involves finding unnatural patterns in communications. Foiling network steganography involves repackaging payload data.