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Re: [P1619-2] EME-2 definition/choice of M1 in middle layer mask update



Colin, I have submitted these two comments for the recirculation sponsor ballot under your name.

Laszlo, feel to free to also submit a sponsor-ballot comment if you feel there needs to be a correction/clarification concerning the issue you raised.

Still looking for a volunteer to create a new EME2 test case. 

Thanks,
-Matt

On Thu, Feb 4, 2010 at 11:48 AM, Colin Sinclair <colin@xxxxxxxxxxxxxx> wrote:
Summary:
 
1. Use of M1 (*always*) in middle mixing layer 129th block needs to be clarified on Figure 2. The psuedo-code is however correct.
 
2. Need one additional test vector of length at least 4129 bytes to ensure correct Mi computation for i >= 2.
 
I guess I could verify a new vector... now that I have corrected my understanding!
 
Cheers,
Colin.
-----Original Message-----
From: Matt Ball [mailto:matthew.v.ball@xxxxxxxxx]
Sent: 04 February 2010 17:39
To: P1619-2@xxxxxxxxxxxxxxxxx
Subject: Re: [P1619-2] EME-2 definition/choice of M1 in middle layer mask update

We need to make sure that these comments are included in the outstanding sponsor ballot before it closes.  I can submit these comments as 'Rogue Comments', unless someone else in the sponsor ballot pool would like to submit them instead.  Can someone summarize the issues into a brief list?

The other issue is that if we decide to create additional test vectors, we need a volunteer to produce such test vectors, and another volunteer to independently verify.  Are there any takers for producing the test vectors?

Thanks!
-Matt

On Thu, Feb 4, 2010 at 9:52 AM, Shai Halevi <shaih@xxxxxxxxxxxx> wrote:
> Finally, I'll just reiterate that, from a standards viewpoint, the test
> vector coverage is not good enough, because the longest 2065 bytes vector
> does not test Mi computation or usage for i >= 2, which is different to
> the i=1 computation. It is /necessary/ to have a 258.x block vector to
> get full coverage of the branches of the algorithm.

I agree. -- Shai



--
Thanks!

Matt Ball, Chair, IEEE P1619 Security in Storage Working Group
Staff Engineer, Sun Microsystems, Inc.
500 Eldorado Blvd, Bldg #5 BRM05-212, Broomfield, CO 80021
Work: 303-272-7580, Cell: 303-717-2717



--
Thanks!

Matt Ball, Chair, IEEE P1619 Security in Storage Working Group
Staff Engineer, Sun Microsystems, Inc.
500 Eldorado Blvd, Bldg #5 BRM05-212, Broomfield, CO 80021
Work: 303-272-7580, Cell: 303-717-2717