Re: WG Last-Call (WGLC) for comments: draft-ietf-ipdvb-sec-req-04.txt

[Michael Noisternig <mnoist@cosy.sbg.ac.at>]

Dear authors,

I'll take the last chance and raise my hand once more. There is only two 
minor issues I have with the current document.

First, I want to repeat what I asked for in a previous mail. There is 
missing some additional case/motivation for ULEsec in the threat 
analysis section:

What you've got is
- you want end-to-end security, and you can use it (but-last paragraph 
of section 3.1),
- you do not need end-to-end security (last paragraph of 3.1).

What is missing is
- you want end-to-end security, but you CANNOT use it.

Therefore I suggest to add the following paragraph at the end of section 
3.1:

ULE links may also be used for communications where the two end-points 
are not under central control (e.g., when browsing a public web site). 
In these cases, it may be impossible to enforce any end-to-end security 
mechanisms. Yet, a common objective is that users can rely on security 
assumptions as of wired links. ULE security could achieve this by 
protecting the vulnerable (in terms of passive attacks) ULE link.


Second, I only realized this now, but you are mixing data (traffic) flow 
confidentiality with data confidentiality. Data confidentiality means 
protecting the payload data, the content, against eavesdropping. Data 
(or traffic) _flow_ confidentiality has to do with concealing addresses, 
packet lengths, or frequency of communication. So identity protection is 
a type of data flow confidentiality, while data confidentiality will 
simply do encryption of the payload. There is several instances of this 
mix-up:

Section 3.3, case 1, should say:
In this scenario, measures must be taken to protect the ULE payload data 
and the identity of ULE Receivers.

Section 4, item 1: Data confidentiality is the major requirement...

Section 4, case 1: Data confidentiality MUST be provided...


Gorry Fairhurst wrote:
> This note starts the WG two week Last-Call for comments for the WG
> document named below:
>
> Security requirements for the Unidirectional Lightweight
> Encapsulation (ULE) protocol
>
> http://www.ietf.org/internet-drafts/draft-ietf-ipdvb-sec-req-04.txt
>
> This Last-Call will end on midnight GMT, 30th September 2007.
>
> Members of the IETF ipdvb WG are now asked to read the above draft and 
> send any issues, comments, or corrections to this mailing list. The WGLC
> procedure is the last chance for this working group to modify/correct
> this document. This document is intended for publication as an 
> INFORMATIONAL RFC.
>
> Please *DO* forward any comments to the list. The document shepherd for
> the process following completion of the WGLC shall be the ipdvb
> Chair (Gorry Fairhurst).
>
> Best wishes,
>
> Gorry Fairhurst
> (ipdvb WG Chair)