Subject: Re: [AVTCORE] FW: New Version Notification for draft-rescorla-avtcore-6222bis-00.txt

From: "Ali C. Begen (abegen)" <[email-masked]>
Date: Sat, 29 Dec 2012 21:48:52 +0000

Kevin,

-----Original Message-----
From: "Ali C. Begen" <[email-masked]>
Date: Monday, November 5, 2012 7:02 PM
To: Kevin Gross <[email-masked]>
Cc: "[email-masked]" <[email-masked]>
Subject: Re: [AVTCORE] FW: New Version Notification for
draft-rescorla-avtcore-6222bis-00.txt

>>Second bullet point in section 4.2 Item (b): Proposes truncating our nice
>>96-bit random CNAME to 48 bits. I think we have an unacceptable
>>opportunity for duplication with this approach. This CNAME should
>>probably use RFC 4648 in which case these CNAMEs
>>take the same form as the per-session CNAMES but differ in the
>>requirement to create once at software initialization. Is it necessary
>>for the different types of CNAMEs to have different appearance?
>
>I don¹t think there is such a requirement and your suggestion makes sense.

Thinking more about this, I think the current text is good. Item (a) uses
48-bit MAC addresses. So, even if we use truncating in item (b), its
collision probability will not be any worse than item (a)'s. Note that
both item (a) and (b) use 17-octet string representation whereas the
per-session CNAME uses 16-octet string representation.

Let me know if you think otherwise.

-acbegen