With the increasing growth of electronic communications, it is becoming important to provide a mechanism for enforcing various security policies on network communications. This paper discusses our implementation of several previously proposed protocols that enforce the Bell LaPadula security model. We also introduce a new protocol called \Quantized Pump" that ooers several advantages, and prese...

In this paper we propose a novel covert channel for exchanging secret information, based on the IP header record route options. Instead of encrypting a secret message or embedding it into a multimedia object, as in traditional steganography, we process the entire message and generate several IP packets with different types to carry the secret information. Thereby we foil an eavesdropper who is ...

Information security and privacy in general are major concerns that impede enterprise adaptation of shared or public cloud computing. Specifically, the concern of virtual machine (VM) physical co-residency stems from the threat that hostile tenants can leverage various forms of side channels (such as cache covert channels) to exfiltrate sensitive information of victims on the same physical syst...

In this paper we propose a novel approach to implement high capacity, covert channel by encoding covert information in the physical layer of common wireless communication protocols. We call our technique Dirty Constellation because we hide the covert messages within a “dirty” constellation that mimics noise commonly imposed by hardware imperfections and channel conditions. The cover traffic in ...

Covert channels have the unique quality of masking evidence that a communication has ever occurred between two parties. For spies and terrorist cells, this quality can be the difference between life and death. However, even the detection of communications in a botnet could be troublesome for its creators. To evade detection and prevent insights into the size and members of a botnet, covert chan...

Network covert channel is a technology that transfers information secretly through the computer network. The length-based covert channel is one of the most popular covert channels. Most of the existing length-based schemes are vulnerable to detections due to the abnormal statistical features of the covert traffic. In this paper, a Skype-based length covert channel SkyLen is proposed. The propos...

This paper uses jamming legitimate transmissions over a slotted ALOHA system as a means of covert communication. The resulting covert channel is found to be source dependent, and to have infinite memory. Hence, a characterization of the capacity of covert communication over such a medium is an inherently complex problem. Employing i.i.d. jamming strategies, this paper derives achievable rates f...

A Guide to Understanding Covert Channel Analysis of Trusted Systems provides a set of good practices related to covert channel analysis. We have written this guide to help the vendor and evaluator communities understand the requirements for covert channel analysis as described in the Department of Defense Trusted Computer System Evaluation Criteria (TCSEC). In an effort to provide guidance, we ...

Covert channels can be utilized to secretly deliver information from high privileged processes to low privileged processes in the context of a high-assurance computing system. In this case study, we investigate the possibility of covert channel establishment via software caches in the context of a framework for component-based operating systems. While component-based operating systems offer sec...

Network covert channels enable a policy-breaking network communication (e.g., within botnets). Within the last years, new covert channel techniques occurred which are based on the capability of protocol switching. There are currently no means available to counter these new techniques. In this paper we present the first approach to effectively limit the bandwidth of such covert channels by intro...