Covert channels have been used as a means to circumvent security measures and leak sensitive data undetectable to an onlooker. While these channels have been used in a lot of networks, their applications on mobile devices have just started to be seen. Recently, many covert channels in Android systems have been presented utilizing various available system resources. This demo aims to show how a ...

For extremely sensitive applications, it may be advantageous for users to transmit certain types of data covertly over the network. This provides an additional layer of security to that provided by the different layers of the protocol stack. In this paper we present a covert side channel that uses the 802.11 MAC rate switching protocol. The covert channel provides a general method to hide commu...

In a real-world network, different hosts involved in covert channel communication run different covert channel software as well as different versions of such software, i.e. these systems use different network protocols for a covert channel. A program that implements a network covert channel for mobile usage thus must be capable of utilizing multiple network protocols to deal with a number of di...

This paper presents a new behavior based covert channel utilizing the database update mechanism of anti-virus software. It is highly covert due to unattended, frequent, automatic signature database update operations performed by the software. The design of the covert channel is described; its properties are discussed and demonstrated by a reference implementation. This paper uses these points t...

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We consider the problem of covert communication over a state-dependent channel, where the transmitter has causal or noncausal knowledge of the channel states. Here, “covert” means that a warden on the channel should observe similar statistics when the transmitter is sending a message and when it is not. When a sufficiently long secret key is shared between the transmitter and the receiver, we d...

Network packet length covert channel modulates secret message bits onto the packet lengths to transmit secret messages. In this paper, a novel network packet length covert channel is proposed. The proposed scheme is based on the empirical distribution function of packet length series of legitimate traffic. Different from the existing schemes, the lengths of packets which are generated by the co...

Covert channels are a security threat for information systems, since they permit illegal flows, and sometimes leaks, of classified data. Although numerous descriptions have been given at a concrete level, relatively little work has been carried out at a more abstract level, outside probabilistic models. In this paper, we propose a definition of covert channels based on encoding and decoding bin...