Subject: CFB Mode correction in 12.8?

From: Erron Criddle <[email-masked]>
Date: Tue, 18 Jul 2000 13:40:26 +0800

To all,

Regarding previous posts and block sizes etc etc, should 12.8 (part 10) read:

FROM:

10) FR is loaded with C11 to C18

TO:

10) FR is loaded with C[BS+3] to C[BS + (BS+2)]

Cheers.

Regards

Erron Criddle
Comasp Ltd.
Level 2, 45 Stirling Hwy
NEDLANDS  WA  6009

Fax: 08 9386 9473
Tel: 08 9386 9534

http://www.comasp.com
[email-masked]

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From: Tom Zerucha <[email-masked]>
Date: Tue, 18 Jul 2000 11:03:02 -0400

> 10) FR is loaded with C[BS+3] to C[BS + (BS+2)]

Yes and no.  The earlier paragraph (the third one in the section)
explains about block sizes <> 8 bytes.

It should say that the procedure/example is using an 8 byte cipher,
and perhaps note your modification to 10 above.

If you describe everything (in this case examples) with mathematical
equations that are correct in all situations, the spec becomes even
harder to understand.  The exact details are described precisely
elsewhere, but because of that complexity this section attempts to
explain it more like pseudocode.

I am not adverse to any adjustment, but I would prefer it in the form
of footnotes or parenthesis just to keep the instructions simpler.

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From: Jon Callas <[email-masked]>
Date: Tue, 18 Jul 2000 13:22:48 -0700

>10) FR is loaded with C[BS+3] to C[BS + (BS+2)]

I changed it to:

FR is loaded with C[BS+3] to C[BS + (BS+2)] (which is C11-C18 for an
8-octet block).

I think this addresses all the concerns?

Thanks.

	Jon

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From: Erron Criddle <[email-masked]>
Date: Wed, 19 Jul 2000 09:51:06 +0800

>I think this addresses all the concerns?

Yes - the more well defined the RFC is, the easier it will be for others to 
understand in the future.

Regards

Erron Criddle
Comasp Ltd.
Level 2, 45 Stirling Hwy
NEDLANDS  WA  6009

Fax: 08 9386 9473
Tel: 08 9386 9534

http://www.comasp.com
[email-masked]