Network Steganography
Wojciech Mazurczyk, Steffen Wendzel, Sebastian Zander, Amir Houmansadr, Krzysztof Szczypiorski · 2016
Network steganography techniques use overt network traffic as a carrier for the secret data. Network steganography techniques can be classified into storage and timing methods based on how the secret data are encoded into the carrier. This chapter introduces various information hiding methods based on the modification of protocol fields or the timing of protocol messages, as well as hybrid approaches such as lost audio steganography (LACK) and retransmission steganography (RSTEG) that combine the modification of protocol fields and protocol message timing to signal hidden information. It discusses techniques that encode hidden information in the timing of protocol messages, also referred to as timing covert channels. Timing channels are always noisy because of the timing inaccuracies at the covert sender and receiver. The intentional retransmissions caused by RSTEG should be kept at a reasonable level to avoid detection.