WLAN steganography revisited
Christian Kraetzer, Jana Dittmann, Ronny Merkel · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2008
Two different approaches for using a sequence of packets of the IEEE 802.11 (WLAN) protocol as cover for a stenographic communication can be found in literature: in 2003 Krzysztof Szczypiorski introduced a method constructing a hidden channel using deliberately corrupted WLAN packets for communication. In 2006 Kraetzer et al. introduced a WLAN stenography approach that works without generating corrupted network packets. This later approach, with hidden storage channel scenario (SCI) and the timing channel based scenario (SCII), is reconsidered here. Fixed parameter settings limiting SCIs capabilities in the implementation (already introduced in 2006) motivated an enhancement. The new implementation of SCI increases the capacity, while at the same time improving the reliability and decreasing the detectability in comparison to the work described in 2006. The timing channel based approach SCII from 2006 is in this paper substituted by a completely new design based on the usage of WLAN Access Point addresses for the synchronization and payload transmission. This new design now allows a comprehensive practical evaluation of the implementation and the evaluations of the scheme, which was not possible with the original SCII before. The test results for both enhanced approaches are summarised and compared in terms of detectability, capacity and reliability.