Subject: RE: Alternatives for Long Term Archiving

From: "Hollerbach, Antje" <[email-masked]>
Date: Thu, 1 Apr 2004 10:04:40 +0200

I think that the use of different archive facilities is unrealistic for
organisations like e.g. hospitals, because the costs are unreasonable,
it is very complex and not practicable.
Real users, such as our university hospital, which source out their
archival system, want to keep their costs as low as possible.
Furthermore, redistribution makes little sense for organisations that
don't outsource.
We need as soon as possible solutions, which can be used for the renewal
of signatures and for the proof of the archiving time. Furthermore
simple protocols for archiving services would be expedient.
The previous documents of LTANS  suit this purpose but not the thoughts
in your mail below!

A. Hollerbach
Center for Information Management (ZIM), University Hospital of
Heidelberg

-----Original Message-----
From: Santosh Chokhani [mailto:[email-masked]]
Sent: Wednesday, March 24, 2004 7:37 PM
To: [email-masked]
Subject: Alternatives for Long Term Archiving

One of the ideas that came out of Seoul meeting (thanks to Larry
Masinter) is to use a key-less approach to trusted archive.  The client
who has vested interest in the secure storage of archived data, can use
Shamir's n of m scheme to submit the archived data to m archive
facilities.  m must be greater than 1 and should be selected based on
availability needs. n must be greater than 1, less than or equal to m,
and should be selected based on the desired degree of protection against
collusion.

If this scheme is used, we may not need any cryptographic operations at
the TAA.

Under this scheme, the LTANS WG would need to still define various
protocol for submission, deletion, and retrieval.  if the idea is
acceptable to the group, it could be the preferred or one of the
approaches to perform archiving.

As the current LTANS documents in the various stages state or imply, the
trusted archive can continue to be used to submit any class of data.

One advantage of the approach is that any document split is not
sensitive even if the original document is sensitive.  However, if the
document requires confidentiality, assuming an adversary could be
monitoring the channels to collect all the splits, the submission and
retrieval of the split should be provided transmission security using
techniques such as SSL or session encryption.  This still is lot easier
than needing to provide long-term encryption for stored data.

To further illustrate one usage of the approach, a client with the need
to provide long-term, non-repudiation of a transaction, could obtain
current time stamp, all the trust anchor, certificates, revocation
information relevant to signatures and time stamp, and package them
using TBD record format and create m splits.  These m split could be
sent to m TAAs using TLS.  Each TLS could provide a pointer to its
split.

When there is a need to retrieve the evidence, n splits could be
retrieved from n TAAs that are available and can be combined to validate
the signatures on the transaction as well as the time stamp.

The approach also offers some redundancy in case some TAAs are not
available, data is corrupted, or the challenger does not trust some of
the TAAs.

Santosh Chokhani 
Orion Security Solutions, Inc. 
1489 Chain Bridge Road, Suite 300 
McLean, Virginia 22101 
(703) 917-0060  Ext. 35 (voice) 
(703) 917-0260 (Fax) 
[email-masked] 
Visit our Web site 
http://www.orionsec.com

---

From: "A. Jerman Blazic" <[email-masked]>
Date: Thu, 1 Apr 2004 10:44:54 +0200

Dear Hollerbach,

I've been silently waiting for an answer like yours. I must admit, that
I unfortunately do not find the discussion going in direction of solving
actual problems. From the position of developer, implementation and
technical advisor it is hard to cope with current standards and proposes
when facing the problem of conserving electronic records. Document bases
are already full and usually in hands of single entity, which sees
appropriate solution as a technology add-on for preservation of existing
and future records. Re-distribution doesn't make much sense, rather
single point of trust is what will IMHO evolve in the next years, the
same scenario as deployed for digital signatures currently. End users
are pressing really hard on us (technology providers) to come up with
solution right this moment. And what is needed is to steer the initial
LTANS course in the right direction and deliver critical missing pieces
in the infrastructure as soon as possible. You may take some of your
time and investigate what solutions do exist already on the market in
the line with technical requirements, legislation and regulation and how
they would solve your problems. The situation is not that bad...

Regards

A.  

> From: [email-masked] 
> [mailto:[email-masked]] On Behalf Of Hollerbach, Antje
> Sent: Thursday, April 01, 2004 10:05 AM
> To: [email-masked]
> Cc: [email-masked]
> Subject: RE: Alternatives for Long Term Archiving
> 
> 
> 
> 
> I think that the use of different archive facilities is 
> unrealistic for organisations like e.g. hospitals, because 
> the costs are unreasonable, it is very complex and not 
> practicable. Real users, such as our university hospital, 
> which source out their archival system, want to keep their 
> costs as low as possible. Furthermore, redistribution makes 
> little sense for organisations that don't outsource. We need 
> as soon as possible solutions, which can be used for the 
> renewal of signatures and for the proof of the archiving 
> time. Furthermore simple protocols for archiving services 
> would be expedient. The previous documents of LTANS  suit 
> this purpose but not the thoughts in your mail below!
> 
> A. Hollerbach
> Center for Information Management (ZIM), University Hospital 
> of Heidelberg
> 
> 
> 
> Masinter) is to use a key-less approach to trusted archive.  
> The client who has vested interest in the secure storage of 
> archived data, can use Shamir's n of m scheme to submit the 
> archived data to m archive facilities.  m must be greater 
> than 1 and should be selected based on availability needs. n 
> must be greater than 1, less than or equal to m, and should 
> be selected based on the desired degree of protection against 
> collusion.
> 
> If this scheme is used, we may not need any cryptographic 
> operations at the TAA.
> 
> Under this scheme, the LTANS WG would need to still define 
> various protocol for submission, deletion, and retrieval.  if 
> the idea is acceptable to the group, it could be the 
> preferred or one of the approaches to perform archiving.
> 
> As the current LTANS documents in the various stages state or 
> imply, the trusted archive can continue to be used to submit 
> any class of data.
> 
> One advantage of the approach is that any document split is 
> not sensitive even if the original document is sensitive.  
> However, if the document requires confidentiality, assuming 
> an adversary could be monitoring the channels to collect all 
> the splits, the submission and retrieval of the split should 
> be provided transmission security using techniques such as 
> SSL or session encryption.  This still is lot easier than 
> needing to provide long-term encryption for stored data.
> 
> To further illustrate one usage of the approach, a client 
> with the need to provide long-term, non-repudiation of a 
> transaction, could obtain current time stamp, all the trust 
> anchor, certificates, revocation information relevant to 
> signatures and time stamp, and package them using TBD record 
> format and create m splits.  These m split could be sent to m 
> TAAs using TLS.  Each TLS could provide a pointer to its split.
> 
> When there is a need to retrieve the evidence, n splits could 
> be retrieved from n TAAs that are available and can be 
> combined to validate the signatures on the transaction as 
> well as the time stamp.
> 
> The approach also offers some redundancy in case some TAAs 
> are not available, data is corrupted, or the challenger does 
> not trust some of the TAAs.
> 
> Santosh Chokhani

---

From: "Santosh Chokhani" <[email-masked]>
Date: Thu, 1 Apr 2004 08:36:14 -0500

Antje Hollerbach:

See responses in-line in [].

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
On Behalf Of Hollerbach, Antje
Sent: Thursday, April 01, 2004 3:05 AM
To: [email-masked]
Cc: [email-masked]
Subject: RE: Alternatives for Long Term Archiving

I think that the use of different archive facilities is unrealistic for
organisations like e.g. hospitals, because the costs are unreasonable, it is
very complex and not practicable. Real users, such as our university
hospital, which source out their archival system, want to keep their costs
as low as possible. Furthermore, redistribution makes little sense for
organisations that don't outsource. We need as soon as possible solutions,
which can be used for the renewal of signatures and for the proof of the
archiving time. Furthermore simple protocols for archiving services would be
expedient. The previous documents of LTANS  suit this purpose but not the
thoughts in your mail below!

[The n of m scheme is being vetted through the process.  Your example shows
that there is a need for a single TAA that relies on computer security and
possibly refreshing time stamp means.  If we were to include n of m scheme
in the standards also, it will be in addition to the ERS approach, not
instead of]. 

A. Hollerbach
Center for Information Management (ZIM), University Hospital of Heidelberg

-----Original Message-----
From: Santosh Chokhani [mailto:[email-masked]]
Sent: Wednesday, March 24, 2004 7:37 PM
To: [email-masked]
Subject: Alternatives for Long Term Archiving

One of the ideas that came out of Seoul meeting (thanks to Larry
Masinter) is to use a key-less approach to trusted archive.  The client who
has vested interest in the secure storage of archived data, can use Shamir's
n of m scheme to submit the archived data to m archive facilities.  m must
be greater than 1 and should be selected based on availability needs. n must
be greater than 1, less than or equal to m, and should be selected based on
the desired degree of protection against collusion.

If this scheme is used, we may not need any cryptographic operations at the
TAA.

Under this scheme, the LTANS WG would need to still define various protocol
for submission, deletion, and retrieval.  if the idea is acceptable to the
group, it could be the preferred or one of the approaches to perform
archiving.

One advantage of the approach is that any document split is not sensitive
even if the original document is sensitive.  However, if the document
requires confidentiality, assuming an adversary could be monitoring the
channels to collect all the splits, the submission and retrieval of the
split should be provided transmission security using techniques such as SSL
or session encryption.  This still is lot easier than needing to provide
long-term encryption for stored data.

To further illustrate one usage of the approach, a client with the need to
provide long-term, non-repudiation of a transaction, could obtain current
time stamp, all the trust anchor, certificates, revocation information
relevant to signatures and time stamp, and package them using TBD record
format and create m splits.  These m split could be sent to m TAAs using
TLS.  Each TLS could provide a pointer to its split.

When there is a need to retrieve the evidence, n splits could be retrieved
from n TAAs that are available and can be combined to validate the
signatures on the transaction as well as the time stamp.

The approach also offers some redundancy in case some TAAs are not
available, data is corrupted, or the challenger does not trust some of the
TAAs.

Santosh Chokhani