Ternary timing covert channel in wireless 802.11

Abstract

Covert channel is one of the remarkable issues which are raised in computer network security. These channels use the computer network's resources to transmit information furtively. Since the purpose of covert channels is to stay hidden from the network security equipments, hence their detection will be difficult. The growth of wireless networks and their broadcast nature make them suitable environments for covert channels' establishment. This study proposes a method to create a covert channel in local area wireless networks by using the temporal characteristics of CSMA/CD algorithm and manipulating the transmission pattern. To increase the bandwidth, hidden data is considered ternary. To assess the covertness of the proposed covert channel, two-sample Kolmogorov-Smirnov test is used. The proposed covert channel achieves the bandwidth of 1620 bps with a high level of security.