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Re: [STDS-802-11-TGBH] padding discussion



I think we should not duplicate information, especially since (as now)

it seems there is some degree of uncertainty about what the maximum

transmission size of a Device ID is (240, as I understand it).

 

NOTE--The maximum size of device ID that can be opacified using this scheme is the maximum size of device ID that can be communicated (see <wherever the 240 limit is specified>) minus the opacification overhead (17 octets (1 for the pad indicator and 16 for the SIV tag) plus padding plus tweak).

 

covers it all.  It enables implementers to work out how big their

device ID can be before it can't be opacified.

 

Thanks,

 

Mark

 

--

Mark RISON, Standards Architect, WLAN   English/Esperanto/Français

Samsung Cambridge Solution Centre       Tel: +44 1223  434600

1 Cambridge Square, Cambridge CB4 0AE   Fax: +44 1223  434601

ROYAUME UNI                             WWW: http://www.samsung.com/uk

 

From: Harkins, Dan <daniel.harkins@xxxxxxx>
Sent: Wednesday, 17 July 2024 15:15
To: STDS-802-11-TGBH@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGBH] padding discussion

 

 

  I think it's helpful for implementers to have a hard number like that. Note that if our consensus was 240 octets it doesn't matter because 240 is wrong as 240 + the opacification overhead = 257 which will end up as 1 because the length is a single octet. We have to be correct. The maximum device ID can be more than 233, it's just that such a device ID cannot be used with the opacification scheme in annex AF. And that's what it says now.

 

  regards,

 

  Dan.

 

--

"the object of life is not to be on the side of the majority, but to

escape finding oneself in the ranks of the insane." – Marcus Aurelius

 

On 7/17/24, 7:03 AM, "Mark Hamilton" <mark.hamilton2152@xxxxxxxxx> wrote:

 

All,

 

I’ll remind the group that (if I recall correctly) we added material explaining the derivation of these “magic numbers” in response to a comment earlier in our process.  I am concerned that reversing that direction, and going back to a more general/vague statement that just has the magic numbers (without the derivation) will result in some voter(s) becoming unhappy again.

 

So, question to the reflector (here):

Are you okay with (or even prefer) to leave unstated the derivation of the required limits on the maximum size of a device ID (or an encoded Device ID, and/or an encrypted opaque identifier – let alone a PASN ID or Measurement ID)?

 

Thanks for any comments/discussion.

 

Mark

 

From: Mark Rison <m.rison@xxxxxxxxxxx>
Sent: Wednesday, 17 July, 2024 5:41
To: STDS-802-11-TGBH@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGBH] padding discussion

 

I'm still struggling with this.

 

From a discussion with the other Mark I'd understood the consensus was

to limit device IDs to 240 octets.  But then in:

 

The overhead of the scheme is 17 octets—1 for the pad indicator and 16 for the SIV tag—plus padding and plus the size of the tweak. Device identifiers that are greater than 233 octets cannot be opacified using this scheme.

Note: 233 is the maximum size of a device ID with no padding and no tweak minus the overhead.

 

I don't understand the 233.

 

I think it would be safer to keep it vague, something like just:

 

NOTE--The maximum size of device ID that can be opacified using this scheme is the maximum size of device ID that can be communicated (see <wherever the 240 limit is specified>) minus the opacification overhead (17 octets (1 for the pad indicator and 16 for the SIV tag) plus padding plus tweak).

 

Thanks,

 

Mark

 

--

Mark RISON, Standards Architect, WLAN   English/Esperanto/Français

Samsung Cambridge Solution Centre       Tel: +44 1223  434600

1 Cambridge Square, Cambridge CB4 0AE   Fax: +44 1223  434601

ROYAUME UNI                             WWW: http://www.samsung.com/uk

 

From: Harkins, Dan <daniel.harkins@xxxxxxx>
Sent: Tuesday, 16 July 2024 21:25
To: STDS-802-11-TGBH@xxxxxxxxxxxxxxxxx
Subject: [STDS-802-11-TGBH] padding discussion

 

 

  Please see document 11-24/1026r1 for proposed changes to address the continued issue with the padding description in the annex (plus the fixing of a typo).

 

  Dan.

 

--

"the object of life is not to be on the side of the majority, but to

escape finding oneself in the ranks of the insane." – Marcus Aurelius

 

 


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