Secure and reliable covert channel

We describe the design, implementation and evaluation of a reliable and secure protocol to establish a covert channel that not only maintains a high degree of stealthiness, but also provides reliability despite temporary data loss as well as data confidentiality. An important feature of our proposed protocol is that it can be embedded in any legitimate channel that is based on IP. In this paper, we describe our protocol using ICMP. In particular, the proposed protocol satisfies four important properties: stealthiness, lightweight, confidentiality and integrity, and reliability.