W3C XML Key Management Working Group Charter

Stephen Farrell, Trinity College Dublin
Shivaram Mysore, Sun Microsystems Inc
W3C Technology and Society Domain Leader
Daniel Weitzner <djw@w3.org>

Status: This document (200211) is the W3C XML Key Management Charter and is an updated version of (200101) that governed until November 2002. This version extends the charter of the Working Group (WG) until July 2003 (7 months) for active work necessary for completing the advancement of the WG's deliverables. The changes in this charter are adjustments to the Duration and Milestones of the Working Group, and a reference to the W3C Current Patent Practice.


The XML Key Management Specification (XKMS 1.0), which was submitted as a W3C Note, builds upon elements defined in the XML Signature specification and anticipates the use of the XML Encryption specification to satisfy these requirements. The proposed work will result in an XML Key Management Recommendation on the basis of the XKMS submission. This proposal explains the need for such an activity from market and technical perspectives, identifies a number of interested companies and recommends that the W3C XKMS working group continue work on its current deliverables.

Table of Contents

Mission Statement

The mission of this working group is to develop a specification of anXML application/protocol that allows a simple client to obtain key information (values, certificates, management or trust data) from a web service. This specification will be based on the XML Key Management Specification (XKMS) which is comprised of two parts -- the XML Key Information Service Specification (X-KISS) and the XML Key Registration Service Specification (X-KRSS).

X-KISS defines a protocol for a Trust service that resolves public key information contained in XML Signature elements. The X-KISS protocol allows a client of such a service to delegate part or all of the tasks required to process <ds:KeyInfo> elements. A key objective of the protocol design is to minimize the complexity of application implementations by allowing them to become clients and thereby to be shielded from the complexity and syntax of the underlying PKI used to establish trust relationships. The underlying PKI may be based upon a different specification such as X.509/PKIX, SPKI or PGP.

X-KRSS defines a protocol for a web service that accepts registration of public key information. Once registered, the public key may be used in conjunction with other web services including X-KISS.


The core scope of this Working Group will be in specifying the necessary protocol elements and Trust Service behavior for the XML Key Management Specification.

The Working Group (WG) will:

  1. Refine, revise and amend the XKMS specification to:
  2. Optionally produce non-normative document(s) that set out best practices for applying XKMS to applications that may include:
  3. Optionally produce a document that extends XKMS to provide support for bulk registration of keys to be embedded in hardware devices (e.g. cable modems and smart-cards).
  4. Propose a new/revised charter for approval by the AC for subsequent work once 1 and 2 have been achieved.

The priority of the group shall be to achieve 1 and 2. However it is advantageous to consider at least one concrete example when considering the future extensibility of a specification and therefore the group may consider 3 at the same time as 1 provided that this does not delay the completion of the priority items.


The following additional requirements must be met by the WG; these requirements may be augmented and extended by the requirements document: 

  1. The PKI Interface must be simple and build upon the <ds:KeyInfo> element specified by XML Signature.
  2. The XML Key Management Activity must be coordinated with and use the deliverables of the XML Protocol, XML Schema, XML Signature and XML Encryption activities to satisfy mandatory requirements addressed by those activities. (See Coordination)
    1. The Working Group must also evaluate XML Query with respect to satisfying its own query query requirements.
  3. All required, recommended, and optional features of the specification must be implemented in at least two independent implementations before being advanced to Proposed Recommendation. These features, and their specification, must be able to interoperate in a secure fashion. Security and privacy concerns must be addressed by the specification.


The working group will not address the following issues:

  1. Design of new cryptographic algorithms.
  2. Issues of non-repudiation, including but not limited to 'technical non-repudiation' and 'contractual non-repudiation'.
  3. Sources of trusted time.
  4. Models and data structures for establishing inter-domain trust, including but not limited to 'cross-certification'.
  5. Expression of existing PKI data structures in XML.
  6. Specification of inter-domain trust semantics.
  7. Authorization and Authorization Assertions.
  8. Attribute Certificates.
  9. Knowledge representation syntax.


This working group will deliver the following:

  1. A W3C Working Draft that captures the requirements 
  2. One or more W3C Recommendation(s) that specify the XML Key Management syntax and protocol
  3. An optional W3C Recommendation that defines a protocol, based on the XML Key Management Recommendation, for bulk registrations.
  4. An optional W3C Note describing best practices for configuring XKMS applications and Trust Services to permit clients that do not provide support for certificate based PKI to interact with existing certificate based applications.
  5. An optional W3C Note describing best practices for configuring XKMS to support chained service applications, including the n-corners transaction model.
  6. An optional W3C Note describing architectural options for using XKMS to support security mechanisms for other Web Services.
  7. If appropriate, draft charters for further work.

Duration and Milestones

This Working Group is scheduled for twenty months. Currently, its expected lifetime is from December 2001 through July 2003.

July 2001
XKMS Workshop
December 2001
Working Group face-to-face meeting (perhaps close to IETF #52)
January 2001
Last Call for Requirements Document (Started in March 2002)
November 2002
Last Call for XKMS & X-Bulk Specification
January 2003
Candidate Recommendation for XKMS & X-Bulk Specification
April 2003
Proposed Recommendation for XKMS & X-Bulk Specification
July 2003
Recommendation for XKMS & X-Bulk Specification

The Working Group can decide to perform tasks in parallel by forming subgroups. These dates are subject to revision due to editorial needs and external scheduling issues; updates will be negotiated with the affected working groups and participants and recorded on the XML Key Management WG home page. Any change in a deliverable date must be brought to the attention of the W3C Domain leader and Director.


This charter, the WG web page, and the mailing list and archives will be publicly accessible.

Coordination with Other Groups

W3C Activities

XML and XML derived activities have become a strategic technology in W3C and elsewhere. 

The Working Group (WG) shall solicit comments from the following W3C working groups on the proposed requirements and during W3C Last Call, the Chair will procure reviews before the specification will be advanced further:

XML Activity
While no dependencies are presently identified, the XML Key Management WG should be prepared to coordinate with the XML Activity (Schema, Core, XML Protocol, Query WGs, etc.) as necessary.
XML Protocol
The XML Key Management WG shall specify a protocol binding of XKMS based on the deliverables of the XML Protocol WG
XML Signature
XML Signature is a Recommendation.
XML Encryption
XML Encryption is a Proposed Recommendation.

At the current time, there are no known dependencies on the work produced by the Working Group.

External Groups

The XML Key Management Working Group should liaise with at least the following groups outside W3C:

The Working Group will cooperate closely with the IETF on the use of XML Key Management to interface to a PKIX conformant PKI. In addition the Working Group will cooperate closely with IETF Working Groups that may develop profiles for making use of the XML Key Management Recommendation (e.g. S/MIME, TLS, IPSEC, DNSSEC)
The Working group will liaise with the IETF SACRED group with the objective of harmonizing the SACRED protocol layer with the X-KRSS roaming operation.
The Working Group will liaise via cross-participation with the Transport, Routing and Packaging project team within ebXML (electronic business XML). ebXML is a joint activity of UN/CEFACT (the United Nations body responsible for UN/EDIFACT), the international EDI standard, and OASIS (Organization for the Advancement of Structured Information Standards).
The Working Group will liaise via cross-participation with the OASIS Security Services Technical Committee developing the Security Assertions Markup Language Specification.
WAP Forum
The Working group will liaise via cross-participation with the WAP Forum to develop a XML Key Management profile for WAP devices.
European Telecommunications Standards Institute
The Working group will consider the impact of the ETSI XML Advanced Electronic Signatures proposal.

Communication Mechanisms

Working group members are expected to participate in an electronic mailing list, periodic teleconferences and face-to-face meetings. The WG consensus venue is the mailing list. Note, straw polls and assessments of consensus may be taken on teleconferences and face-to-face meetings which will then be sent to the list via minutes. If those decision are not opposed or questioned on the list, they naturally stand as the WG's consensus.

(See Participants for information on the roles and commitments of working group members.)

NOTE: The proceedings of this Working Group are public.

Group Home Page

In order to maintain shared context of the group and to provide access to the proceedings of the group, the Chair maintains a web page at: http://www.w3.org/2001/XKMS/

Active participants are expected to have ready access to this page and be familiar with its contents.

Mailing List

Participants must subscribe to and participate in the (www-xkms@w3.org) mailing list.


As necessary, the Chair may convene teleconferences periodically for the purpose of quickly addressing and resolving open issues and tracking action items and deliverables.

The Chair is responsible for producing an agenda at least 24 hours in advance of each call, posting it along with the call details to the mailing list, and causing minutes of the call to be posted promptly after the call.

A public IRC channel may be available to complement/coordinate teleconference discussion. However, the IRC conversation is not necessarily part of the record: it must be stated on the teleconference as an IRC message is not necessarily a sufficient communication to the others on the teleconference.

Face to Face Meetings

Meeting notice, advance agenda, and posting of minutes shall follow W3C timing rules. See the Working Group's Minutes and Meetings for upcoming meetings and past minutes.

Communication with the Public

This working group is public.

Patent Disclosure

W3C promotes an open working environment. Whenever possible, technical decisions should be made unencumbered by intellectual property right (IPR) claims.

This is a Royalty Free Working Group as described in the 24 January 2002 version of W3C's Current Patent Practice. The Current Patent Practice defines and formalizes the policy this Working Group has followed since its inception: to produce deliverables that may be implemented on a royalty-free basis. The Current Patent Practice Note also introduces some processes (e.g., related to the formation of PAGs) that were not previously explicit.

Working Group participants disclose patent claims by sending email to <patent-issues@w3.org>. Because this is a public Working Group the disclosure must also be sent to the publicly archived <www-xkms@w3.org> list. Please see Current Patent Practice for more information about disclosures.


This section describes the expectations and requirements of Staff, Member, and Public commitment necessary for this Working Group to be started -- and eventually succeed. The actual roles (chair, author, editor, contributor, implementor) and definitions are to be defined by W3C Process and to be compatible with those of the XML Signature Working Group Contributor Policies.

Contributors to this working group are expected to commit to 15% (6 hours a week). Commitments for Author and Editor positions are 25% and 35% respectively. The Chairing commitment is expected to require 40% of a single person's time.

4.4.1 W3C Team commitment

The W3C Team will dedicate 20% of a single person to this activity for WG participation and the Staff Contact role: coordinating with other Staff Contacts of the identified WGs, and advising the Chair and WG on W3C Process and publishing requirements.

4.4.2 W3C Member commitment

This is a public working group and anyone may contribute to the Working Group. However, at the outset of the Activity, the interested W3C member organizations are expected to identify one or more individual contributors to the Working Group and the level of contribution at which they are willing to participate.

4.4.3 Public/Individual commitment

Public contributors are welcome to commit to the completion of any action item or to the fulfillment of the roles described in the Contributor Policies. Note, materials sent to the public list are part of the W3C site and subject to W3C policies and licenses. The W3C holds the copyright of all Working Group deliverables (e.g., specifications).