Subject: [secdir] [new-work] WG Review: Reputation Services (repute)

From: IESG Secretary <[email-masked]>
Date: Tue, 27 Sep 2011 14:21:16 -0700 (PDT)

A new IETF working group has been proposed in the Applications 
Area.  The IESG has not made any determination as yet. The following 
draft charter was submitted, and is provided for informational purposes 
only. Please send your comments to the IESG mailing list ([email-masked]) 
by Tuesday, October 4, 2011. 

Reputation Services (repute)
-----------------------------------------
Status: Proposed Working Group
Last Updated: 2011-09-13

Chair(s):
TBD

Applications Area Director(s):
  Pete Resnick ([email-masked])
  Peter Saint-Andre ([email-masked])

Applications Area Advisor:
  Pete Resnick ([email-masked])

Mailing Lists:
  General Discussion: [email-masked]
  To Subscribe:	      https://www.ietf.org/mailman/listinfo/repute
  Archive:	      http://www.ietf.org/mail-archive/web/repute/

Description of Working Group:

In the open Internet, making a meaningful choice about the handling
of content requires an assessment of its safety or "trustworthiness".
This is based on a trust metric for the owner (identity) of an
identifier associated with the content, to distinguish (likely)
good actors from bad actors.  The generic term for such information
is "reputation".  This working group will develop mechanisms for
reputation reporting by independent services.  One mechanism will be
for a basic assessment of trustworthiness.  Another will provide a
range of attribute/value data that is used as input to such an
assessment.  Each service determines the attributes it reports.

Various mechanisms have been developed for associating a verified
identifier with email content, such as with SPF (RFC4408) and DKIM
(RFC4871).  An existing reputation query mechanism is
Vouch-by-Reference (RFC5518). It provides a simple Boolean
response concerning a domain name used for email.  The current working
group effort will expand upon this, to support additional
applications -- such as Web pages and hosts -- and a wider range of
reporting information.

Given the recent adoption of domain name verification for email,
by SPF and DKIM, the most obvious initial use case for reputation is
for email.  Inbound email filters that perform message authentication
can obtain a verified domain name and then consult a reputation service
provider to make a determination (perhaps also based on other
factors) of whether or not the content is desirable and take
appropriate action with respect to delivery, routing or rejection.
	
Another possible use case is identity-based evaluation of web
content using technologies such as the DKIM-derived DOSETA
(work in progress).

This working group will produce specifications for:

   * the detailed requirements for reporting

   * an end-to-end system architecture in which reporting occurs

   * the mechanisms and formats for reporting

Two mechanisms are under consideration:

   * simple -- a reputation is expressed in a simple manner,
               via records in the DNS
	       (see draft-kucherawy-reputation-query-dns)

   * extended -- a response can contain more complex information
	         useful to an assessor, reported over HTTP using
                 an encoding such as XML or JSON
	         (see draft-kucherawy-reputation-query-http)

The syntactic and semantic aspects of mechanisms and formats will be
designed to be application-independent and portable (i.e., reputation
provider-independent).  By distinguishing reporting information
(format) from reporting mechanism (channel), the specifications
will permit adaptation to support reporting through additional
channels.  Limited application-specific tailoring will be
provided for email, to demonstrate the approach, which can be
applied for supportting additional applications.  The design and
specification will also permit adaptation to support reporting
through additional transport channels.

Items that are specifically out of scope for this work:

   * Specific actions to be taken in response to a reputation reply.
     It is up to assessors (i.e., the consumers of reputation data)
     to determine this.  Non-normative illustrations, however, can
     be included to demonstrate possible uses of reputation data
     in a particular context.

   * Selection of what data might be valid as the subject of a
     reputation query.  It is up to reputation service providers and
     assessors to select which qualities of a body of data might
     be useful input to reputation evaluation.

   * Concerns about methods of verifying domain names that are used
     for email reputation.  A verified domain name is a starting point
     for this work; the means by which it was obtained and the
     "meaning" of the name or its verification are matters for
     discussion elsewhere.

   * Algorithms to be applied to aggregated feedback in order to
     compute reputations.  These are part of a back-end system, usually
     proprietary, and not appropriate for specification as part of
     a query/reply framework and protocol.

The initial draft set:
	draft-kucherawy-reputation-model
	draft-kucherawy-reputation-media-type
	draft-kucherawy-reputation-query-http
	draft-kucherawy-reputation-query-dns
	draft-kucherawy-reputation-query-udp
	draft-kucherawy-reputation-vocab-identity

Goals and Milestones:

Mar 2012:	Informational document, defining the problem space
		and solution architecture, to the IESG for publication.

Mar 2012:	Specification for the multi-attribute reporting
		data structure, to the IESG for publication.

May 2012:	Informational document, defining the vocabulary
		for providing reputation in the email sphere, to the
		IESG for publication.

Jul 2012:  	Specification defining the simple
		query mechanism, to the IESG for publication.

Jul 2012:  	Specification for the extended
		query mechanism, to the IESG for publication.

Oct 2012:  	Informational document, discussing issues
		of data transparency, redress, meta-reputation
		and other important operational considerations, to the
		IESG for publication.

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