Long-Term Archive and Notary Services (ltans)
---------------------------------------------

 Charter
 Last Modified: 2006-05-16

 Current Status: Active Working Group

 Chair(s):
     Carl Wallace  <cwallace@orionsec.com>
     Tobias Gondrom  <tgondrom@opentext.com>

 Security Area Director(s):
     Russ Housley  <housley@vigilsec.com>
     Sam Hartman  <hartmans-ietf@mit.edu>

 Security Area Advisor:
     Russ Housley  <housley@vigilsec.com>

 Mailing Lists: 
     General Discussion:ietf-ltans@imc.org
     To Subscribe:      ietf-ltans-request@imc.org
         In Body:       subscribe
     Archive:           http://www.imc.org/ietf-ltans

Description of Working Group:

In many scenarios, users need to be able to ensure and prove the
existence and validity of data, especially digitally signed data, in a
common and reproducible way over a long and possibly undetermined 
period
of time.

Cryptographic means are useful, but they do not provide the whole
solution. For example, digital signatures (generated with a particular
key size) might become weak over time due to improved computational
capabilities, new cryptanalytic attacks might "break" a digital
signature algorithm, public key certificates might be revoked or 
expire,
and so on.

Complementary methods covering potential weaknesses are necessary.

Long-term non-repudiation of digitally signed data is an important
aspect of PKI-related standards. Standard mechanisms are needed to
handle routine events, such as expiry of signer's public key 
certificate
and expiry of trusted time stamp authority certificate. A single
timestamp is not sufficient for this purpose. Additionally, the 
reliable
preservation of content across change of formats, application of
electronic notarizations, and subsequent notary services require
standard solutions.

The objective of the LTANS working group is to define requirements, 
data
structures and protocols for the secure usage of the necessary archive
and notary services. First, the requirements for the long-term archive
will be collected. Based on that information we will develop a protocol
to access archive services supplying long-term non-repudiation for
signed documents and define common data structures and formats. Upon
completion of the archive-related specifications, we will address
'notary services' in a similar way. The term 'notary services' is not
clearly defined. The working group will determine which functions need
standards, including transformation of documents from one format to
another without losing the value of evidence, electronic notarization,
and further verification of legal validity of signed documents. We will
determine the needs via the requirements paper and act upon the results
accordingly. 

Work done by the IETF Working Groups PKIX, S/MIME and XMLDSIG will be
used as the basis to define those structures and protocols. For 
example,
the Internet-Drafts "Archive Time-Stamps Syntax (ATS)" and "Trusted
Archive Protocol (TAP)" and RFC 3029, "Data Validation and Certificate
Server Protocols (DVCS)", contain applicable concepts.

 Goals and Milestones:

   Done         Initial requirements for long-term archive I-D 

   Done         Initial data structures for long-term archive I-D 

   Done         Revised requirements for long-term archive I-D 

   Done         Revised data structures for long-term archive I-D 

   Done         Initial requirements for notary services I-D 

   Done         Initial protocol for long-term archive I-D 

   Done         Revised requirements for notary services I-D 

   Done         WG Last call requirements for long-term archive I-D 

   Nov 2005       Submit requirements for long-term archive to IESG as 
                informational 

   Nov 2005       Submit data structures for long-term archive to IESG as 
                proposed standard 

   Dec 2005       Protocol revisions for long-term archive I-D 

   Jan 2006       WG Last call protocol for long-term archive I-D 

   Jan 2006       Submit protocol for long-term archive to IESG as proposed 
                standard 

   Jan 2006       WG Last call requirements for notary services I-D 

   Jan 2006       Submit requirements for notary services to IESG as 
                informational 

   Mar 2006       Recharter or close the working group 

   Done         WG Last call data structures for long-term archive I-D 


 Internet-Drafts:

Posted Revised         I-D Title   <Filename>
------ ------- --------------------------------------------
Feb 2004 Oct 2006   <draft-ietf-ltans-reqs-09.txt>
                Long-Term Archive Service Requirements 

Feb 2004 May 2006   <draft-ietf-ltans-ers-07.txt>
                Evidence Record Syntax (ERS) 

Jul 2005 Jun 2006   <draft-ietf-ltans-ltap-02.txt>
                Long-term Archive Protocol (LTAP) 

Sep 2005 May 2006   <draft-ietf-ltans-ers-scvp-01.txt>
                Using SCVP to Convey Long-term Evidence Records 

 Request For Comments:

  None to date.