Transition Request: Canonical EXI to Proposed Recommendation

This is a request to publish a Proposed Recommendation of the Canonical EXI.. 
The document was previously published as a Candidate Recommendation on 03 November 2016.


Document Title:
---------------
    Canonical EXI


Document URI:
-------------
    Editor's copy is located at:
    http://www.w3.org/XML/EXI/docs/canonical/canonical-exi.html


Abstract
--------
    Any EXI document is part of a set of EXI documents that are logically 
    equivalent within an application context, but which vary in physical 
    representation based on differences permitted by the [EXI Format 1.0]. 
    This specification describes a relatively simple method for generating 
    a physical representation, the canonical form, of an EXI document that 
    accounts for the permissible differences. An example of the applications 
    targeted by this specification is one that needs to guarantee non-repudiation 
    using XML Signature yet allows certain flexibility for intermediaries to 
    reconstitute the documents before they reach final destination without 
    breaking the signatures. Note that two documents may have differing 
    canonical forms yet still be equivalent in a given context based on more 
    elaborate application-specific equivalence rules which is out of scope of 
    this specification. 
    http://www.w3.org/XML/EXI/docs/canonical/canonical-exi.html#abstract


Status of the document
----------------------
    http://www.w3.org/XML/EXI/docs/canonical/canonical-exi.html#status


Record of the WG's decision to request advancement
--------------------------------------------------
    Decision was made during the telecon on 2018-04-16.
    https://www.w3.org/2018/04/16-exi-minutes.html#item01


Report of important changes to the document
-------------------------------------------
    Changes are enumerated in Changes section:
    http://www.w3.org/XML/EXI/docs/canonical/canonical-exi.html#N68143


Evidence that the document satisfies group's requirements
---------------------------------------------------------
    There is no requirement document. However, the Working Group
    received reviews from users of the EXI specification.

    It is also worth mentioning that ISO/IEC 15118 (V2G CI) standard
    is referencing this specification for use in the V2G communication
    interface. The use of EXI in V2G, and the desire therein for 
    canonical form of EXI originally constituted the motivation behind 
    starting to work on this document.


Evidence that dependencies with other groups were met (or not)
--------------------------------------------------------------
    The only dependency is on the EXI specification itself.


Evidence that the document has received wide review
---------------------------------------------------
    It received 3 external comments from 2 organizations since CR.
    One of the 2 organizations has a Canonical EXI implementation.
    Those three comments were all processed as issues (please see below section for issues list).

    It also received 2 internal comments. Those are listed below.
    https://lists.w3.org/Archives/Public/public-exi/2018Jan/0003.html
    https://lists.w3.org/Archives/Public/public-exi/2018Feb/0001.html

    They are the result of careful reviews involving implementation efforts..


Evidence that issues have been formally addressed
-------------------------------------------------
    No new issues have been raised from outside the WG. 

    The issues raised within the WG have been processed with the expected 
    due process in resolving issues among group members. 

    ISSUE-120: Canonical EXI should use XSD 1.1 date and time types intead of those of XSD 1.0
    https://www.w3.org/2005/06/tracker/exi/issues/120

    ISSUE-121: Canonical EXI needs clarification on how to canonicalize dateTime values
    https://www.w3.org/2005/06/tracker/exi/issues/121

    ISSUE-122: DateTime Canonicalization should preserve seconds field
    https://www.w3.org/2005/06/tracker/exi/issues/122


Objections:
-----------
    None.


Implementation information:
---------------------------
    The WG developed test cases tailored to address each feature of Canonical EXI 
    Candidate Recommendation.

    Currently, there are implementations available from two working group 
    member organizations, and one from non-member organization. 

    For each feature, the WG demonstrated two implementations interoperate,
    and produced an implementation report.
    https://www.w3.org/XML/EXI/implementation-report-c14n/
    In addition, a non-member organization reported that a third implementation 
    successfully interoperates with the other two implementations.

    There is not an optional feature in Canonical EXI.

    The tests thoroughly cover the specification. The coverage of the test
    was reviewed carefully by members.


Patent disclosures
------------------
    No patent disclosures were made.




Takuki Kamiya
Fujitsu Laboratories of America

Received on Friday, 20 April 2018 18:31:51 UTC