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IP Covert Channel Detection

Published:01 April 2009Publication History
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Abstract

A covert channel can occur when an attacker finds and exploits a shared resource that is not designed to be a communication mechanism. A network covert channel operates by altering the timing of otherwise legitimate network traffic so that the arrival times of packets encode confidential data that an attacker wants to exfiltrate from a secure area from which she has no other means of communication. In this article, we present the first public implementation of an IP covert channel, discuss the subtle issues that arose in its design, and present a discussion on its efficacy. We then show that an IP covert channel can be differentiated from legitimate channels and present new detection measures that provide detection rates over 95%. We next take the simple step an attacker would of adding noise to the channel to attempt to conceal the covert communication. For these noisy IP covert timing channels, we show that our online detection measures can fail to identify the covert channel for noise levels higher than 10%. We then provide effective offline search mechanisms that identify the noisy channels.

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    • Published in

      cover image ACM Transactions on Information and System Security
      ACM Transactions on Information and System Security  Volume 12, Issue 4
      April 2009
      96 pages
      ISSN:1094-9224
      EISSN:1557-7406
      DOI:10.1145/1513601
      Issue’s Table of Contents

      Copyright © 2009 ACM

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      Publication History

      • Published: 1 April 2009
      • Accepted: 1 November 2008
      • Revised: 1 July 2008
      • Received: 1 March 2006
      Published in tissec Volume 12, Issue 4

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