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
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




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.

本文件是互联网工程任务组(IETF)的产品。它代表了IETF社区的共识。它已经接受了公众审查,并已被互联网工程指导小组(IESG)批准出版。有关BCP的更多信息,请参见RFC 5741第2节。

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at


Copyright Notice


Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved.

版权所有(c)2014 IETF信托基金和确定为文件作者的人员。版权所有。

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents ( 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.

本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(自本文件出版之日起生效。请仔细阅读这些文件,因为它们描述了您对本文件的权利和限制。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本,并提供简化BSD许可证中所述的无担保。

1. Pervasive Monitoring Is a Widespread Attack on Privacy
1. 无处不在的监控是对隐私的广泛攻击

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.


2. The IETF Will Work to Mitigate Pervasive Monitoring
2. IETF将致力于缓解普遍的监控

"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.

“缓解”是一个技术术语,并不意味着能够完全防止或挫败攻击。缓解PM的协议不会阻止攻击,但会显著改变威胁。(参见RFC 4949第24页的图表,了解术语“攻击”和“威胁”之间的关系。)这会显著增加攻击成本,迫使隐藏的内容公开,或使攻击更容易被检测到,可能是以后。

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


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
3. 工艺说明

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
4. 安全考虑

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.


5. Acknowledgements
5. 致谢

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 and the lists.

我们要感谢IETF 88技术全体会议的与会者的反馈。特别感谢以下人士提供有用的建议或意见:贾里·阿尔科、弗雷德·贝克、马克·布兰切特、蒂姆·布雷、斯科特·布里姆、兰迪·布什、布赖恩·卡彭特、贝诺特·克莱斯、艾莉莎·库珀、戴夫·克罗克、斯宾塞·道金斯、艾弗里·多里亚、卫斯理·艾迪、阿德里安·法雷尔、约瑟夫·洛伦佐·霍尔、菲利普·哈勒姆·贝克、泰德·哈迪、萨姆·哈特曼、保罗·霍夫曼、,比约恩·霍尔曼、罗斯·霍斯利、乔尔·贾格利、斯蒂芬·肯特、艾略特·李尔、巴里·莱巴、特德·莱蒙、苏布拉曼尼亚·穆内萨米、埃里克·诺德马克、皮特·雷斯尼克、彼得·圣安德烈、安德鲁·沙利文、肖恩·特纳、尼古拉斯·韦弗、斯特凡·温特和劳埃德·伍德。此外,我们还要感谢所有就如何改善互联网安全和隐私提出建议或在各种IETF邮件列表(如ietf@ietf.org和perpass@ietf.org名单。

6. Informative References
6. 资料性引用

[IETF88Plenary] IETF, "IETF 88 Plenary Meeting Materials", November 2013, <>.


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

[RFC1984]IAB,IESG,Carpenter,B.和F.Baker,“IAB和IESG关于加密技术和互联网的声明”,RFC 1984,1996年8月。

[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.

[RFC3552]Rescorla,E.和B.Korver,“关于安全考虑的RFC文本编写指南”,BCP 72,RFC 3552,2003年7月。

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

[RFC4844]Daigle,L.和互联网架构委员会,“RFC系列和RFC编辑器”,RFC 48442007年7月。

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

[RFC4949]Shirey,R.,“互联网安全术语表,第2版”,RFC 49492007年8月。

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

[RFC5741]Daigle,L.,Kolkman,O.,和IAB,“RFC流,标题和样板”,RFC 57412009年12月。

[RFC6962] Laurie, B., Langley, A., and E. Kasper, "Certificate Transparency", RFC 6962, June 2013.

[RFC6962]Laurie,B.,Langley,A.和E.Kasper,“证书透明度”,RFC 69622013年6月。

[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.

[RFC6973]Cooper,A.,Tschofenig,H.,Aboba,B.,Peterson,J.,Morris,J.,Hansen,M.,和R.Smith,“互联网协议的隐私考虑”,RFC 69732013年7月。

Authors' Addresses


Stephen Farrell Trinity College Dublin Dublin 2 Ireland


   Phone: +353-1-896-2354
   Phone: +353-1-896-2354

Hannes Tschofenig ARM Ltd. 6060 Hall in Tirol Austria

Hannes Tschofenig ARM Ltd.位于奥地利蒂罗尔的6060大厅