comment on 06-369r2 -- Security Association Model for SPC-4

Kevin D Butt kdbutt at us.ibm.com
Wed Aug 30 13:13:03 PDT 2006


Formatted message: <A HREF="r0608302_f.htm">HTML-formatted message</A>

Ralph,
I already sent this note to you offline, but now I wish to send it 
slightly modified for all to see.
This proposal adds definitions but does nothing to specify HOW to create 
an SA.	With the WHAT but without the HOW TO create portion, I fear this 
will push vendors to implement before the HOW TO is defined.  This may 
tend to push for vendor specific methods to create an SA without having a 
standard method defined.  This will defeat the purpose of having a 
standard.  IBM Tape is strongly opposed to voting for something that is 
incomplete and begs for vendor-specific solutions because there is no 
standard method to do something that is described.  We believe that the 
HOW TO needs to be added in before this should be allowed into the 
standards.
Thanks,
Kevin D. Butt
SCSI & Fibre Channel Architect, Tape Firmware
MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
Tel: 520-799-2869 / 520-799-5280
Fax: 520-799-2723 (T/L:321)
Email address: kdbutt at us.ibm.com
http://www-03.ibm.com/servers/storage/ 
Ralph Weber <roweber at ieee.org> 
Sent by: owner-t10 at t10.org
08/26/2006 09:36 AM
To
t10 at t10.org
cc
Subject
Re: comment on 06-369r2 -- Security Association Model for SPC-4
For my part, I fail to see how an SA can be established
until there is a definition of what an SA is.
I consider the SA definition so fundamental that having
the definition phrased in traditional SCSI terms is
critical to me. This is why (as SPC-4 editor) I am
working on 06-369rx.
While it seems simpler to have the SA definition in
a working draft for easy reference by those writing 
SA creation proposals (and there might be two of these 
coming, one for authenticated SAs and one for 
unauthenticated SAs), if the majority of CAP sees
things differently, I will of course abide by that
decision.
I still plan to press for a vote on 06-369.
All the best,
.Ralph
Gideon Avida wrote: 
* From the T10 Reflector (t10 at t10.org), posted by:
* "Gideon Avida" <gideon at decru.com>
*
While I understand the motivation behind proposal 06-369, I don't think
Decru can vote for it for similar reasons voiced against proposal 06-225 
in
Colorado Springs. From the SSC-3 minutes: "Kevin Butt from IBM raised the
issue that this proposal relies on an already established security
association. It is the foundation for this key wrapping and we are opposed
to this without a method in SCSI defined to create a Security 
Association."
On a related topic, Decru would like to propose the use of public key
cryptography as an alternative means for securing data encrypting keys. 
Due
to time constraints between the meetings, I only have a rough overview 
that
I'd like to discuss in Nashua (it's currently submitted to the SSC-3
agenda). Please see http://www.t10.org/ftp/t10/document.06/06-389r0.pdf. 
If
there is interest in this approach, I will flesh out the details of the
proposal by the Las Vegas meeting.
Thanks,
Gideon
-----Original Message-----
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of
Black_David at emc.com
Sent: Friday, August 25, 2006 2:49 PM
To: Gerry.Houlder at seagate.com; t10 at t10.org
Subject: RE: comment on 06-369r2 -- Security Association Model for SPC-4
* From the T10 Reflector (t10 at t10.org), posted by:
* Black_David at emc.com
*
Gerry,
It is also unclear if this security association method is required for
all
"security protocols" supported in SECURITY PROTOCOL IN/ OUT commands
or
just the tape protocol (which is the only one described in SPC-4 at
the
moment).
The function of the proposed security association abstraction is to
separate generation of symmetric cryptographic keys from use of those
keys
in order to enable mix/match of security mechanisms across that boundary
(separation of key generation from key usage).	If a "security protocol"
does not generate keys for use in other SCSI functionality, it can
ignore the whole concept of a security association.
The tape protocol is going to specify a means of encrypting encryption
keys in order to transfer them securely to tape devices that have
onboard
encryption - to do so, the protocol needs to use another key.  This may
sound recursive (need a second key to protect first key, how is the
second key protected?), but fortunately, the recursion ends with what
is called a "key exchange protocol" that generates a shared secret from
non-secret communication exchanges plus some mathematics.  One of the
reasons for putting forward security association text now is that there
is a possibility that SSC-3 will want to specify multiple key exchange
protocols, and a structure in which multiple such protocols can co-exist
cleanly is important to avoid chaos.
Thanks,
--David
----------------------------------------------------
David L. Black, Senior Technologist
EMC Corporation, 176 South St., Hopkinton, MA  01748
+1 (508) 293-7953	      FAX: +1 (508) 293-7786
black_david at emc.com	   Mobile: +1 (978) 394-7754
----------------------------------------------------
-----Original Message-----
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf 
Of Gerry.Houlder at seagate.com
Sent: Friday, August 25, 2006 3:44 PM
To: t10 at t10.org
Subject: comment on 06-369r2 -- Security Association Model for SPC-4
* From the T10 Reflector (t10 at t10.org), posted by:
* Gerry.Houlder at seagate.com
*
While reading through the new section 5.13, I thought the information
was
not organized in the best order for understanding. 5.13.1 and 5.13.2
introduce tables without describing what they are for. Clause 5.13.3
finally starts defining a "security association" and what it is used
for.
This should become the first clause in 5.13 because it provides a
basis for
understanding the stuff in the other clauses.
It is also unclear if this security association method is required for
all
"security protocols" supported in SECURITY PROTOCOL IN/ OUT commands
or
just the tape protocol (which is the only one described in SPC-4 at
the
moment).
I would like to see a more generic model that starts with material
from
5.13.1,5.13.3, and 5.13.4; then moves on to describe the choices made
for
the minimum SA parameters, etc. for the tape protocol. It should also
state
that the tape protocol details do not necessarily apply to protocols
that
reference other documents for their description.
*
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