Re: [secdir] Secdir review of draft-ietf-geopriv-uncertainty-03

"Takeshi Takahashi" <> Wed, 08 October 2014 00:57 UTC

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From: Takeshi Takahashi <>
To: 'Martin Thomson' <>
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Date: Wed, 08 Oct 2014 09:59:01 +0900
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Subject: Re: [secdir] Secdir review of draft-ietf-geopriv-uncertainty-03
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Hello Martin,

I see, thank you for the clarification.

Kind regards,

-----Original Message-----
From: Martin Thomson [] 
Sent: Wednesday, October 8, 2014 6:19 AM
To: Takeshi Takahashi
Cc:;; The IESG;
Subject: Re: Secdir review of draft-ietf-geopriv-uncertainty-03

Thanks for the review,

The draft is, as you note, in two pieces.  However, when I took this to the working group in two parts, the overwhelming consensus there was to merge the documents.  As a result, it becomes standards track with large informational sections.  The normative parts are small, and so the use of 2119 language is also restricted.

As for your concerns about security, the general issue of altering parts of an object is only a concern if you have partial integrity mechanisms.  The security considerations of RFC 4119 cover a lot of that (the use of S/MIME for confidentiality and integrity, for instance).

On 7 October 2014 02:24, Takeshi Takahashi <> wrote:
> Hello,
> I have reviewed current version of this document as part of the 
> security directorate's ongoing effort to review all IETF documents 
> being processed by the IESG.  These comments were written primarily 
> for the benefit of the security area directors.  Document editors and 
> WG chairs should treat these comments just like any other last call comments.
> This draft provides lots of information on how to handle uncertainty 
> and confidence.
> It also defines a schema for describing confidence information.
> I believe this document is very helpful for readers.
> It outlines assorted techniques in a very clear way.
> I think this draft is almost ready, but I have clarification questions 
> as follows.
> 1. standards track (std), or informational?
> I am not sure what would be the criteria for being a std RFC, but I 
> feel like that this draft talks as if it is an informational draft.
> I do not mean that I object to make it as a std rfc, but clarification 
> is appreciated.
> A std RFC specifies the interfaces that communication parties need to 
> follow, IMHO.
> The RFC 3863 and 5139 is std RFCs since they define data format/schema 
> each communication party needs to follow.
> The RFC 3693, which this draft is updating, is an informational RFC 
> and provides lots of useful knowledge, but it does not force anything 
> to communication parties.
> How is the case of this draft?
> I know that the draft specifies a schema for the confidence 
> information, but I feel like this is rather smaller part of the issues 
> discussed in this draft.
> It talks about schemes to handle uncertainty, but it does not define a 
> single scheme to handle uncertainty. (It outlines several techniques, 
> but implementers need to consider which techniques to use, and they 
> can implement different techniques, IMHO.)
> To sum up, I would appreciate if you could clarify why the draft is in 
> the std rfc.
> 2. why this document is not split into two documents?
> This is related to the issue 1.
> Here are my understanding of the sections.
> Section 7 defines the confidence schema.
> I understood that this document normatively defines this schema and 
> implementers need to follow this schema.
> On the other hand, sections 2 - 5 provides helpful information, but 
> the draft does not mandate implementers to do anything.
> I have understood that implementers can use arbitrary techniques 
> (including the techniques introduced in this document) to handle uncertainty.
> I wonder whether it would have been easier to have separate drafts for 
> the issues; i.e., the content described in section 7 goes to std RFC 
> while the rest goes to another informational rfc.
> 3. content in sections 2-5
> Thank you for your elaboration.
> This is very helpful to get knowledge on the uncertainty manipulation.
> If this document goes to a std RFC, I would expect to see sentences 
> such as "SHOULD/MUST/is recommended to use the techniques to handle 
> uncertainty", in these sections.
> 4. security considerations
> If the confidence information is maliciously altered, does it cause 
> trouble to the information receiver?
> (I think the RFC 4119 (and RFC 3694) does not address the need to 
> protect confidence information.)
> Information sender sents a location information with high confidence 
> value, but the information receiver received the information with 
> falsified low confidence value.
> I guess this could hinder some decision making of the information 
> receiver in some case.
> So, I think it would be safer to say something like that we should 
> implement schemes to protect the values that is defined outside the 
> scope of this draft, etc.
> Kind regards,
> Take
> ---
> Takeshi Takahashi, Ph.D.,
> Senior Researcher at the National Institute of Information and 
> Communications Technology, Japan