Network Working Group                                         S. Farrell
Internet-Draft                                    Trinity College Dublin
Intended status: BCP                                       H. Tschofenig
Expires: May 24, 2014                                  November 20, 2013

                   Pervasive Monitoring is an Attack


   The IETF has consensus that pervasive monitoring is a technical
   attack that should be mitigated in the design of IETF protocols,
   where possible.

Status of this Memo

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   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on May 24, 2014.

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1.  It's an Attack

   [[Note: This draft is written as if IETF consensus has been
   established for the text.]]

   The technical plenary of IETF 88 [IETF88Plenary] discussed pervasive
   monitoring and participants had strong agreement that this was an
   attack and one that should be mitigated where possible via the design
   of protocols that make pervasive monitoring significantly more
   expensive or infeasible.  Such pervasive surveillance requires the
   monitoring party to take actions that are indistinguishable from an
   attack on Internet communications.  This Best Current Practice (BCP)
   documents that consensus.

   For the purposes of this BCP "pervasive monitoring" means very
   widespread privacy-invasive gathering of protocol artefacts including
   application content, protocol meta-data (such as headers) or keys
   used to secure protocols.  Other forms of traffic analysis, for
   example, timing or measuring packet sizes can also be used for
   pervasive monitoring.  A fuller problem statement with more examples
   and description can be found in [ProblemStatement].

   Note that the term "attack" is used here in a techincal sense that
   differs somewhat from the natural English usage.  In particular, the
   term, when used technically, implies nothing about the motivation of
   the bad-actor mounting the attack, who is still called a bad-actor no
   matter what one really thinks about their motivation.  We also use
   the term in the singluar here, even though pervasive monitoring in
   reality may require a multi-faceted set of co-ordinated attacks.

   The motivation behind pervasive monitoring is not particularly
   relevant for this document, but can range from non-targeted nation-
   state surveillance, to legal but privacy-unfriendly purposes by
   commercial enterprises, to illegal purposes by criminals.  The same
   techniques can be used in each case, regardless of motivation, and we
   cannot defend against the most nefarious actors while allowing
   monitoring by other actors no matter how benevolent some might
   consider those.  As technology continues to advance rapidly
   techniques that have been shown to work but were once only accessible
   to nation-state actors become accessible to non-nation-state actors,
   so mitigating this threat is not only relevant when considering
   nation-state bad actors.

2.  And we'll work to Mitigate the Attack

   The IETF also have consensus to, where possible, work to mitigate the
   technical parts of the pervasive monitoring attack, in just the same

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   way as we do with any other protocol vulnerability.

   There are various ways in which IETF protocols can be designed in
   order to mitigate pervasive monitoring, but those will change over
   time as mitigation and attack techniques develop and so are not
   described here.  This BCP simply records the consensus to design
   protocols so as to mitigate the attack, where possible.

   Note that more limited-scope monitoring to assist with network
   management or that is required in order to operate the network or an
   application are not considered pervasive monitoring.  There is though
   a clear potential for network management mechanisms to be abused as
   part of pervasive monitoring, so this tension needs careful
   consideration in protocol design: making networks unmanageable in
   order to mitigate pervasive monitoring would not be an acceptable
   outcome, but equally, ignoring pervasive monitoring in designing
   network management mechanisms would go against the consensus
   documented in this BCP.  An appropriate balance will likely emerge
   over time as real instances of this tension are considered.

   It is also important to note that the term "mitigation" is also a
   technical term that does not necessarily imply an ability to
   completely prevent or thwart an attack.  In this case, designing IETF
   protocols to mitigate pervasive monitoring will almost certainly not
   completely prevent such from happening, but can increase the cost
   significantly or force what was covert monitoring to be more overt,
   or more likely to be detected (possibly later) via other means.  And
   even where the IETF has done this work well and that has been fully
   deployed, there will still be some privacy-relevant information that
   will inevitably be disclosed by protocols.

   Finally, we note that the IETF is not equipped to tackle the non-
   technical aspects of mitigating pervasive surveillance.  We hope that
   others will step forward to tackle those.

3.  Process Note

   In the past, architectural statements of this sort, e.g., [RFC1984]
   and [RFC2804] have been published as joint products of the IESG and
   IAB.  However, since those documents were published, the IETF and IAB
   have separated their publication "streams" as described in [RFC4844]
   and [RFC5741].  This document was initiated by both the IESG and IAB,
   but it is being published as an IETF-stream consensus document,
   having garnered the consensus of the IETF as approved by the IESG.

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4.  Security Considerations

   This BCP is all about privacy.  More information about the
   relationship between security and privacy threats can be found in
   [RFC6973].  Section 5.1.1 of [RFC6973] specifically addresses
   surveillance as a combined security-privacy threat.

5.  IANA Considerations

   There are none.  We hope the RFC editor deletes this section before

6.  Acknowledgements

   We would like to thank the participants of the IETF 88 technical
   plenary for their feedback.  Additionally, we would like to thank all
   those who contributed to their suggestions on how to improve Internet
   security on various IETF mailing lists, such as the and
   the lists.

   Thanks in particular to the following for useful comments: Jari
   Arkko, Marc Blanchet, Benoit Claise, Spencer Dawkins, Russ Housley,
   Joel Jaeggli, Eliot Lear, Barry Leiba, Ted Lemon, Erik Nordmark, Pete

7.  Informative References

              IETF, "IETF 88 Plenary Meeting Materials",  URL:
              Nov 2013.

              Richard Barnes, "Pervasive Monitoring: Problem Statement",
               URL: To-Be-Published, Nov 2013.

   [RFC1984]  IAB, IESG, Carpenter, B., and F. Baker, "IAB and IESG
              Statement on Cryptographic Technology and the Internet",
              RFC 1984, August 1996.

   [RFC2804]  IAB and IESG, "IETF Policy on Wiretapping", RFC 2804,
              May 2000.

   [RFC4844]  Daigle, L. and Internet Architecture Board, "The RFC
              Series and RFC Editor", RFC 4844, July 2007.

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   [RFC5741]  Daigle, L., Kolkman, O., and IAB, "RFC Streams, Headers,
              and Boilerplates", RFC 5741, December 2009.

   [RFC6973]  Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
              Morris, J., Hansen, M., and R. Smith, "Privacy
              Considerations for Internet Protocols", RFC 6973,
              July 2013.

Authors' Addresses

   Stephen Farrell
   Trinity College Dublin
   Dublin,   2

   Phone: +353-1-896-2354

   Hannes Tschofenig


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