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diff --git a/doc/rfc/rfc7258.txt b/doc/rfc/rfc7258.txt new file mode 100644 index 0000000..b3195a4 --- /dev/null +++ b/doc/rfc/rfc7258.txt @@ -0,0 +1,339 @@ + + + + + + +Internet Engineering Task Force (IETF) S. Farrell +Request for Comments: 7258 Trinity College Dublin +BCP: 188 H. Tschofenig +Category: Best Current Practice ARM Ltd. +ISSN: 2070-1721 May 2014 + + + Pervasive Monitoring Is an Attack + +Abstract + + Pervasive monitoring is a technical attack that should be mitigated + in the design of IETF protocols, where possible. + +Status of This Memo + + This memo documents an Internet Best Current Practice. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Further information on + BCPs is available in Section 2 of RFC 5741. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc7258. + +Copyright Notice + + Copyright (c) 2014 IETF Trust and the persons identified as the + document authors. All rights reserved. + + This document is subject to BCP 78 and the IETF Trust's Legal + Provisions Relating to IETF Documents + (http://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + + + + + + + + + +Farrell & Tschofenig Best Current Practice [Page 1] + +RFC 7258 Pervasive Monitoring Is an Attack May 2014 + + +1. Pervasive Monitoring Is a Widespread Attack on Privacy + + Pervasive Monitoring (PM) is widespread (and often covert) + surveillance through intrusive gathering of protocol artefacts, + including application content, or protocol metadata such as headers. + Active or passive wiretaps and traffic analysis, (e.g., correlation, + timing or measuring packet sizes), or subverting the cryptographic + keys used to secure protocols can also be used as part of pervasive + monitoring. PM is distinguished by being indiscriminate and very + large scale, rather than by introducing new types of technical + compromise. + + The IETF community's technical assessment is that PM is an attack on + the privacy of Internet users and organisations. The IETF community + has expressed strong agreement that PM is an attack that needs to be + mitigated where possible, via the design of protocols that make PM + significantly more expensive or infeasible. Pervasive monitoring was + discussed at the technical plenary of the November 2013 IETF meeting + [IETF88Plenary] and then through extensive exchanges on IETF mailing + lists. This document records the IETF community's consensus and + establishes the technical nature of PM. + + 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. The term is + used here to refer to behavior that subverts the intent of + communicating parties without the agreement of those parties. An + attack may change the content of the communication, record the + content or external characteristics of the communication, or through + correlation with other communication events, reveal information the + parties 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". + We also use the term in the singular here, even though PM in reality + may consist of a multifaceted set of coordinated attacks. + + In particular, the term "attack", used technically, implies nothing + about the motivation of the actor mounting the attack. The + motivation for PM can range from non-targeted nation-state + surveillance, to legal but privacy-unfriendly purposes by commercial + enterprises, to illegal actions by criminals. The same techniques to + achieve PM can be used regardless of motivation. Thus, we cannot + defend against the most nefarious actors while allowing monitoring by + other actors no matter how benevolent some might consider them to be, + since the actions required of the attacker are indistinguishable from + other attacks. The motivation for PM is, therefore, not relevant for + how PM is mitigated in IETF protocols. + + + +Farrell & Tschofenig Best Current Practice [Page 2] + +RFC 7258 Pervasive Monitoring Is an Attack May 2014 + + +2. The IETF Will Work to Mitigate Pervasive Monitoring + + "Mitigation" is a technical term that does not imply an ability to + completely prevent or thwart an attack. Protocols that mitigate PM + will not prevent the attack but can significantly change the threat. + (See the diagram on page 24 of RFC 4949 for how the terms "attack" + and "threat" are related.) This can significantly increase the cost + of attacking, force what was covert to be overt, or make the attack + more likely to be detected, possibly later. + + IETF standards already provide mechanisms to protect Internet + communications and there are guidelines [RFC3552] for applying these + in protocol design. But those standards generally do not address PM, + the confidentiality of protocol metadata, countering traffic + analysis, or data minimisation. In all cases, there will remain some + privacy-relevant information that is inevitably disclosed by + protocols. As technology advances, techniques that were once only + available to extremely well-funded actors become more widely + accessible. Mitigating PM is therefore a protection against a wide + range of similar attacks. + + It is therefore timely to revisit the security and privacy properties + of our standards. The IETF will work to mitigate the technical + aspects of PM, just as we do for protocol vulnerabilities in general. + The ways in which IETF protocols mitigate PM will change over time as + mitigation and attack techniques evolve and so are not described + here. + + Those developing IETF specifications need to be able to describe how + they have considered PM, and, if the attack is relevant to the work + to be published, be able to justify related design decisions. This + does not mean a new "pervasive monitoring considerations" section is + needed in IETF documentation. It means that, if asked, there needs + to be a good answer to the question "Is pervasive monitoring relevant + to this work and if so, how has it been considered?" + + In particular, architectural decisions, including which existing + technology is reused, may significantly impact the vulnerability of a + protocol to PM. Those developing IETF specifications therefore need + to consider mitigating PM when making architectural decisions. + Getting adequate, early review of architectural decisions including + whether appropriate mitigation of PM can be made is important. + Revisiting these architectural decisions late in the process is very + costly. + + While PM is an attack, other forms of monitoring that might fit the + definition of PM can be beneficial and not part of any attack, e.g., + network management functions monitor packets or flows and anti-spam + + + +Farrell & Tschofenig Best Current Practice [Page 3] + +RFC 7258 Pervasive Monitoring Is an Attack May 2014 + + + mechanisms need to see mail message content. Some monitoring can + even be part of the mitigation for PM, for example, certificate + transparency [RFC6962] involves monitoring Public Key Infrastructure + in ways that could detect some PM attack techniques. However, there + is clear potential for monitoring mechanisms to be abused for PM, so + this tension needs careful consideration in protocol design. Making + networks unmanageable to mitigate PM is not an acceptable outcome, + but ignoring PM would go against the consensus documented here. An + appropriate balance will emerge over time as real instances of this + tension are considered. + + Finally, the IETF, as a standards development organisation, does not + control the implementation or deployment of our specifications + (though IETF participants do develop many implementations), nor does + the IETF standardise all layers of the protocol stack. Moreover, the + non-technical (e.g., legal and political) aspects of mitigating + pervasive monitoring are outside of the scope of the IETF. The + broader Internet community will need to step forward to tackle PM, if + it is to be fully addressed. + + To summarise: current capabilities permit some actors to monitor + content and metadata across the Internet at a scale never before + seen. This pervasive monitoring is an attack on Internet privacy. + The IETF will strive to produce specifications that mitigate + pervasive monitoring attacks. + +3. Process Note + + In the past, architectural statements of this sort, e.g., [RFC1984] + and [RFC2804], have been published as joint products of the Internet + Engineering Steering Group (IESG) and the Internet Architecture Board + (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 after + discussions in both the IESG and IAB, but is published as an IETF- + stream consensus document, in order to ensure that it properly + reflects the consensus of the IETF community as a whole. + +4. Security Considerations + + This document 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. + + + + + + + +Farrell & Tschofenig Best Current Practice [Page 4] + +RFC 7258 Pervasive Monitoring Is an Attack May 2014 + + +5. 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 or comments: Jari Arkko, Fred Baker, Marc + Blanchet, Tim Bray, Scott Brim, Randy Bush, Brian Carpenter, Benoit + Claise, Alissa Cooper, Dave Crocker, Spencer Dawkins, Avri Doria, + Wesley Eddy, Adrian Farrel, Joseph Lorenzo Hall, Phillip + Hallam-Baker, Ted Hardie, Sam Hartmann, Paul Hoffman, Bjoern + Hoehrmann, Russ Housley, Joel Jaeggli, Stephen Kent, Eliot Lear, + Barry Leiba, Ted Lemon, Subramanian Moonesamy, Erik Nordmark, Pete + Resnick, Peter Saint-Andre, Andrew Sullivan, Sean Turner, Nicholas + Weaver, Stefan Winter, and Lloyd Wood. 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 ietf@ietf.org and the + perpass@ietf.org lists. + +6. Informative References + + [IETF88Plenary] + IETF, "IETF 88 Plenary Meeting Materials", November 2013, + <http://www.ietf.org/proceedings/88/>. + + [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. + + [RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC + Text on Security Considerations", BCP 72, RFC 3552, July + 2003. + + [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. + + [RFC6962] Laurie, B., Langley, A., and E. Kasper, "Certificate + Transparency", RFC 6962, June 2013. + + + + + +Farrell & Tschofenig Best Current Practice [Page 5] + +RFC 7258 Pervasive Monitoring Is an Attack May 2014 + + + [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 + Ireland + + Phone: +353-1-896-2354 + EMail: stephen.farrell@cs.tcd.ie + + + Hannes Tschofenig + ARM Ltd. + 6060 Hall in Tirol + Austria + + EMail: Hannes.tschofenig@gmx.net + URI: http://www.tschofenig.priv.at + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Farrell & Tschofenig Best Current Practice [Page 6] + |