Network Working Group                                         S. Farrell
Internet-Draft                                    Trinity College Dublin
Intended status: BCP                                       H. Tschofenig
Expires: June 6, 2014                                   December 3, 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

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on June 6, 2014.

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1.  It's an Attack

   [[Note (to be removed before publication): This draft is written as
   if IETF consensus has been established for the text.]]

   The technical plenary of IETF 88 [IETF88Plenary] discussed pervasive
   monitoring.  Such pervasive surveillance requires the monitoring
   party to take actions that are indistinguishable from an attack on
   Internet communications.  Participants at that meeting therefore
   expressed strong agreement that this was an attack that should be
   mitigated where possible via the design of protocols that make
   pervasive monitoring significantly more expensive or infeasible.
   This Best Current Practice (BCP) formally documents that consensus,
   having been through an IETF last call.

   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, correlation, timing or measuring packet sizes can also be
   used for pervasive monitoring.

   The term "attack" is used here in a technical sense that differs
   somewhat from common English usage.  In common English usage, an
   "attack" is an aggressive action perpetrated by an opponent, intended
   to enforce the opponent's will on the attacked party.  In the
   Internet, the term is used to refer to a behavior that subverts the
   intent of a communicator without the agreement of the parties to the
   communication.  It may change the content of the communication,
   record the content of the communication, or through correlation with
   other communication events or attempts, reveal information the
   communicator did not intend to be revealed.  It may also have other
   effects that similarly subvert the intent of a communicator.
   [RFC4949] contains a more complete definition for the term "attack"
   as used here.  We also use the term in the singular here, even though
   pervasive monitoring in reality may require a multi-faceted set of
   coordinated attacks.

   In particular, the term "attack", when used technically, implies
   nothing about the motivation of the actor mounting the attack.  The
   motivation behind pervasive monitoring is not 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
   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 them to be.  As technology
   advances, techniques that were once only available to extremely well

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   funded actors become more widely accessible.  Mitigating this attack
   is therefore a protection against wider usage of pervasive

2.  And We Will Continue to Mitigate the Attack

   The IETF also has consensus to, where possible, work to mitigate the
   technical parts of the pervasive monitoring attack, in just the same
   way as we continually do for these and any other protocol

   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.

   More limited-scope monitoring to assist with network management that
   is required in order to operate the network or an application is not
   considered pervasive monitoring.  There is though a clear potential
   for such limited monitoring 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 a
   technical term that does not necessarily imply an ability to
   completely prevent or thwart an attack.  As in common English usage,
   this term is used here in the sense of "make less severe, serious, or
   painful."  [OED] In this case, designing IETF protocols to mitigate
   pervasive monitoring will almost certainly not completely prevent
   such from happening, but can significantly increase the cost of such
   monitoring 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.

   While RFC 4949 does not contain a definition for the term mitigation,
   we prefer it here to the term countermeasure which is defined in RFC
   4949 since the latter term is more often understood to mean putting
   in place a more fully effective mitigation of an attack.

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   Finally, we note that the IETF is not equipped to tackle the non-
   technical aspects of mitigating pervasive surveillance.  Others need
   to step forward to tackle those if pervasive monitoring is to be
   fully addressed.

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 published as an IETF-stream consensus document, having
   garnered the consensus of the IETF as approved by the IESG.

4.  Security Considerations

   This BCP is entirely 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.  Thanks in particular to the following
   for useful suggestions that resulted in changes to this text: Jari
   Arkko, Fred Baker, Marc Blanchet, Brian Carpenter, Benoit Claise,
   Spencer Dawkins, Adrian Farrel, Russ Housley, Joel Jaeggli, Eliot
   Lear, Barry Leiba, Ted Lemon, Erik Nordmark, Pete Resnick, Peter
   Saint-Andre, and Sean Turner.  Additionally, we would like to thank
   all those who contributed suggestions on how to improve Internet
   security and privacy or who commented on this on various IETF mailing
   lists, such as the and the lists.

7.  Informative References


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

   [OED]      Stevenson, Angus, "Oxford Dictionary of English", Oxford
              University Press
              definition/english/mitigate, 2010.

   [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.

   [RFC4949]  Shirey, R., "Internet Security Glossary, Version 2",
              RFC 4949, August 2007.

   [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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