Internationalized Domain Names in Applications, Revised (idnabis) ----------------------------------------------------------------- Charter Last Modified: 2009-09-01 Current Status: Active Working Group Chair(s): Vinton Cerf Applications Area Director(s): Lisa Dusseault Alexey Melnikov Applications Area Advisor: Lisa Dusseault Mailing Lists: General Discussion:idna-update@alvestrand.no To Subscribe: http://www.alvestrand.no/mailman/listinfo/idna-update Archive: http://www.alvestrand.no/pipermail/idna-update/ Description of Working Group: The original Internationalized Domain Name (IDN) WG specified rules for the use of characters other than Latin A(a)-Z(z), digits 0-9 and the hyphen (-) in domain names in RFC3490, RFC3491 and RFC3492 in 2002 (published in 2003 and often referenced collectively as "IDNA2003"). These documents depend on RFC 3454 and were tied to Unicode version 3.2. An update to the current version (5.x) is required to accommodate additional scripts. In addition, experience has shown that significant improvements could be made in the protocol as presently specified. This WG is chartered to decouple IDNA from specific versions of Unicode using algorithms that define validity based on Unicode properties. It is recognized that some explicit exceptions may be necessary in any case, but attempts will be made to minimize these exceptions. Additional goals: - Separate requirements for valid IDNs at registration time (insertion of names into DNS zone files), vs. at resolution time (looking up those names) - Review, and if necessary revise, the algorithms and rules for handling right to left character sequences in an IDN context to allow labels based on additional scripts and languages and to make presentation as predictable as reasonably possible. - Permit use of some scripts that were inadvertently excluded by the original protocols. - Ensure practical stability of validity algorithms for IDNs. The constraints of the original IDN WG still apply to IDNABIS, namely to avoid disturbing the current use and operation of the domain name system, and for the DNS to continue to allow any system to resolve any domain name in a consistent way. The client-based approach of the original IDN work will be maintained -- substantially new protocols or mechanisms are not in scope. In particular, IDNs continue to use the "xn--" prefix and the same ASCII-compatible encoding, and the bidirectional algorithm follows the same basic design. The specifications are initially organized as four documents: overview and rationale, protocol, table algorithm, and improvements to the bidirectional algorithm. These documents are to be used as the basis for the discussion of the general direction of the work. This working group will be providing extended public review of the output of a design team that has been working on improvement of the IDNA specifications. This review-based approach is being used in part because of the way the work was undertaken by the team; in particular, the design team has been working with IETF visibility and has solicited and received significant amounts of technical review already from IETF participants and from others including experts in the Unicode specifications and the use of scripts in languages. If the public review provided by this Working Group confirms the basic method outlined in the input documents, it is expected that the working group will be able to respond with any needed changes and close in a short period of time. If technical issues arise that indicate a fundamentally different approach must be taken from the one outlined above, it is anticipated that this working group would close, and a new one with an appropriate charter would be considered. This work is intended to specify an improved means to produce and use stable and unambiguous IDN identifiers. There are a variety of generally unsolvable problems, notably the problem of characters that are confusingly similar in appearance (often known as the "phishing" problem) that are not specifically part of the scope of the WG although some of the preliminary results of the design team suggest that the improvements contemplated in the specifications might mitigate some of the ways in which the current IDNA specifications can be abused for phishing purposes. While it is referenced from the original IDNA2003 package, the original Stringprep specification, RFC 3454, is not formally part of the IDNA package and will not be altered by this work. The work will update or obsolete RFC 3490. It is not expected to continue to use Nameprep (RFC 3491). Nameprep is used by other specifications; determining how (or whether) to update those specifications and, consequently, the long-term status of Nameprep, are not part of this effort. The method for ASCII-compatible ("ACE") encoding of IDNs, "Punycode" (RFC 3492) will not be revised by this WG. Subject to the more general constraints described above, the WG is permitted to consider changes that are not strictly backwards- compatible. For any such change that is recommended, it is expected to document the reasons for the change, the characters affected, and possible transition strategies. The assumptions outlined above are considered critical to the WG constituted by this charter. The WG will stop work and recommend that a new charter be generated if it concludes that any of the following are necessary to meet its goals: (i) A change to the "punycode" algorithm or to the ACE approach to encoding names in the DNS. (ii) A change to the ACE prefix from "xn--" (iii) A change to the basic approach taken in the design team documents (Namely: independence from Unicode version and reduction of dependency on character mapping ) Goals and Milestones: Apr 2008 WG formation May 2008 Decision on form and structure of the WG document set Sep 2008 WG Last Call on WG document set Nov 2008 IETF Last Call on WG document set Internet-Drafts: Posted Revised I-D Title ------ ------- -------------------------------------------- Apr 2008 Sep 2009 The Unicode code points and IDNA May 2008 Sep 2009 Internationalized Domain Names for Applications (IDNA): Background, Explanation, and Rationale May 2008 Sep 2009 Internationalized Domain Names in Applications (IDNA): Protocol May 2008 Sep 2009 Right-to-left scripts for IDNA Oct 2008 Sep 2009 Internationalized Domain Names for Applications (IDNA): Definitions and Document Framework May 2009 Sep 2009 Mapping Characters in IDNA Request For Comments: None to date.