Multiscale Stepping-Stone Detection: Detecting Pairs of Jittered Interactive Streams by Exploiting Maximum Tolerable Delay

  • David L. Donoho
  • Ana Georgina Flesia
  • Umesh Shankar
  • Vern Paxson
  • Jason Coit
  • Stuart Staniford
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2516)


Computer attackers frequently relay their attacks through a compromised host at an innocent site, thereby obscuring the true origin of the attack. There is a growing literature on ways to detect that an interactive connection into a site and another outbound from the site give evidence of such a “stepping stone.” This has been done based on monitoring the access link connecting the site to the Internet (Eg. [7,11, 8]). The earliest work was based on connection content comparisons but more recent work has relied on timing information in order to compare encrypted connections.

Past work on this problem has not yet attempted to cope with the ways in which intruders might attempt to modify their traffic to defeat stepping stone detection. In this paper we give the first consideration to constraining such intruder evasion. We present some unexpected results that show there are theoretical limits on the ability of attackers to disguise their traffic in this way for sufficiently long connections.

We consider evasions that consist of local jittering of packet arrival times (without addition and subtraction of packets), and also the addition of superfluous packets which will be removed later in the connection chain (chaff).

To counter such evasion, we assume that the intruder has a “maximum delay tolerance.” By using wavelets and similar multiscale methods, we show that we can separate the short-term behavior of the streams — where the jittering or chaff indeed masks the correlation — from the long-term behavior of the streams — where the correlation remains.

It therefore appears, at least in principle, that there is an effective countermeasure to this particular evasion tactic, at least for sufficiently long-lived interactive connections.


Network intrusion detection Evasion Stepping Stone Interactive Session Multiscale Methods Wavelets Universal Keystroke Interarrival Distribution 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Aldous, D.L.: Probability Approximations Via the Poisson Clumping Heuristic. Springer-Verlag, New York. January 1989MATHGoogle Scholar
  2. 2.
    Lindgren, G., Leadbetter, M.R., and Rootzen, H.: Extremes and related properties of stationary sequences and processes. Springer, New York (1983). Russian translation; Nauka: Moscow (1988).Google Scholar
  3. 3.
    Shimomura, T. and Markoff, J.: Takedown. The pursuit and capture of Kevin Mit-nick, America’s most wanted computer outlaw-by the man who did it. Hyperion. December 1995.Google Scholar
  4. 4.
    Mallat, S.: A Wavelet Tour of Signal Processing. Academic Press. Second Edition, 2000.Google Scholar
  5. 5.
    Meyer, Y.:Wavelets: Algorithms and Applications. SIAM. May 1993Google Scholar
  6. 6.
    Stoll, C.: The Cuckoo’s Egg: Tracking a Spy through the Maze of Computer Espionage. Pocket Books. October 2000Google Scholar
  7. 7.
    Staniford-Chen, S. and Heberlein, L.: Holding Intruders Accountable on the Internet. Proceedings of the 1995 IEEE Symposium on Security and Privacy, Oakland, CA (1995)Google Scholar
  8. 8.
    Zhang, Y. and Paxson, V.: Detecting stepping stones. Proceedings of the 9th USENIX Security Symposium, Denver, Colorado, August 2000.
  9. 9.
    Paxson, V. and Floyd, S.: Wide-Area Traffic: The Failure of Poisson Modeling. IEEE/ACM Transactions on Networking, Vol. 3(3), June 1995, 226–244Google Scholar
  10. 10.
    Wavelab Toolbox for Wavelet Analysis. Requires Matlab. http://www-stat. stanford. edu/ wavelab
  11. 11.
    Yoda, K. and Etoh, H.: Finding a Connection Chain for Tracing Intruders, In: Guppens, F., Deswarte, Y., Gollamann, D. and Waidner, M. (eds): 6th European Symposium on Research in Computer Security-ESORICS 2000 LNCS-1985, Toulouse, France, Oct 2000Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2002

Authors and Affiliations

  • David L. Donoho
    • 1
  • Ana Georgina Flesia
    • 1
  • Umesh Shankar
    • 2
  • Vern Paxson
    • 3
  • Jason Coit
    • 4
  • Stuart Staniford
    • 4
  1. 1.Department of StatisticsStanford UniversityStanfordUSA
  2. 2.Department of Computer ScienceUniversity of California at BerkeleyBerkeley
  3. 3.International Computer Science InstituteBerkeley
  4. 4.Silicon DefenseDavisUSA

Personalised recommendations