Implementation of a Covert Channel in the 802.11 Header

Covert channels are an immense cause of security concern because they can be used to pass malicious messages. The messages could be in form of computer virus, spy programs, terrorist messages, etc. Most available techniques proposed covert channels that use the upper layers of the OSI model. In this paper, we discuss a novel covert channel in the data link layer dedicated to wireless local area networks. Depending on the configuration of the network, the covert channel uses either sequence control or initial vector fields, or both of them. We present also some measurements to protect the proposed covert channel against steganalysis processes and sniffing attack. Finally, the performance of proposed covert channel is compared with the available common TCP/IP covert channels regarding the offered bandwidth and the imperceptibly.