Re: [6lo] Review Request for ipv6-over-nfc-07

최영환 <> Mon, 03 July 2017 08:08 UTC

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From: =?utf-8?B?7LWc7JiB7ZmY?= <>
To: "Pascal Thubert (pthubert)" <>, Samita Chakrabarti <>, Dave Thaler <>, "" <>, lo <>
CC: James Woodyatt <>, =?utf-8?B?67CV7KCV7IiY?= <>
Thread-Topic: Review Request for ipv6-over-nfc-07
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Date: Mon, 3 Jul 2017 08:08:23 +0000
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Subject: Re: [6lo] Review Request for ipv6-over-nfc-07
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Dear Pascal,

First of all, thanks for your comments.
Please, see in-line bellows:

Younghwan Choi

From: Pascal Thubert (pthubert) []
Sent: Thursday, June 15, 2017 7:43 PM
To: Samita Chakrabarti <>om>; Dave Thaler <>om>; 최영환 <>kr>;; lo <>
Cc: James Woodyatt <>
Subject: RE: Review Request for ipv6-over-nfc-07

Dear authors ;

Thanks for incorporating a nonce in the computation of the privacy address. This addresses my concern. It would have been good to insist that you are doing it in the security section as well, but the text there confirms that the address is not repeated on the next connection so we should be all set. Also in the security section, I’m not sure what to do with this text:


   However, malicious tries for one connection of a long-lived link with
   NFC technology are not secure, so the method of deriving interface
   identifiers from 6-bit NFC Link layer addresses is intended to
   preserve global uniqueness when it is possible.  Therefore, it
   requires a way to protect from duplication through accident or
  forgery and to define a way to include sufficient bit of entropy in
   the IPv6 interface identifier, such as random EUI-64.

I fail to understand the first sentence and the paragraph reads as a problem statement, but for what?  Seems that section 4.3 does now provide the required entropy, correct?

>>  Yes, it’s correct. I support your comments. The paragraph have been done before I added the new texts in section 4.3. I’ll revise the paragraph in security section for the next version.

About section 4.5, I think some more text could be useful to assign the role of 6LBR.
If 2 similar devices meet (say 2 handeheld), whether one is 6LR/LBR. How would that be decided?
When they are different, if there is a fixed device (a payment terminal, say) or provides connectivity as a router, then it makes sense that it is 6LBR.
This could be described so we would not end up with 2 devices that cannot talk because they only do 6LN.

>>  You’re right. The current version does not mention the role of 6LBR when two NFC-devices meet. I’m working to add more texts for the role in the next version. Maybe, the new version (-08) including reflection about all feedback from you and James will be produced soon! Thanks a lot.



From: Samita Chakrabarti []
Sent: mardi 6 juin 2017 02:16
To: Pascal Thubert (pthubert) <<>>; Dave Thaler <<>>; 최영환 <<>>;<>; lo <<>>
Cc: James Woodyatt <<>>
Subject: Review Request for ipv6-over-nfc-07

Hello Dave, Pascal, James and WG members:

ipv6-over-nfc-07 has just been published and the author mentions that he had addressed the comments from Pascal and Dave.

 Pascal and Dave,  would you please have sometime to review version 07 to check if your comments are addressed?

I have appended the excerpt from IETF98 meeting minutes for your reference.
This document is due for WG LC if  it looks okay.

James, you are shepherd for NFC draft -- please let us know if you are okay with the document's next step.


As per IETF98 meeting minutes:

2 IPv6 over NFC                                    Younghwan Choi was presented by Younghawn Choi on updates and
  discussed comments from WG and NFC forum. The draft was reviewed by NFC forum, no more comments
  from NFC forum. The author likes to move to WGLC.

  Dave Thaler:IID generation changed as a result of previous meeting

  Pascal: Replacing 6 bit address with hashing function with fixed parameters. Scanning is still
  easy. How is it different?
  YC: offset. Dave: offset should be random to add entropy, not predictable.
  Gabriel: offset may not be a right name. Nonce would be better.
  Samita: need reviewers before WGLC. Pascal, Dave, would you volunteer?
  Pascal will do the review and Dave agreed to review the final update.
---------- Forwarded message ----------
From: 최영환 <<>>
Date: Sun, Jun 4, 2017 at 5:02 PM
Subject: RE: [6lo] Request for IETF99@Prague 6lo Agenda items
To: Samita Chakrabarti <<>>
Cc: Gabriel Montenegro <<>>
Hello Samita,

I’ve submitted the new version of ipv6-over-nfc (-07). The document is ready for review.

Best regards,
Younghwan Choi