Mutual Anonymous Communications: A New Covert Channel Based on Splitting Tree MAC

Known covert channel based on splitting algorithms in Medium Access Control (MAC) protocols requires the receiver´s knowledge of the sender´s identity. In this paper we present a new covert channel that does not have this restriction. In such a channel, multiple senders may operate independently without knowing each other, and the receiver can learn the transmitted information without knowing the identity of any covert sender a priori. These properties make the channel robust to malfunctioning senders, and more importantly help protect the secrecy of senders´ identity which is essential for covert communications. We also analyze the capacity of our proposed covert channel.