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Internet Engineering Task Force (IETF) G. Lozano Request for Comments: 8909 ICANN Category: Standards Track November 2020 ISSN: 2070-1721

                 Registry Data Escrow Specification

Abstract

 This document specifies the format and contents of data escrow
 deposits targeted primarily for domain name registries.  The
 specification is designed to be independent of the underlying objects
 that are being escrowed, and therefore it could also be used for
 purposes other than domain name registries.

Status of This Memo

 This is an Internet Standards Track document.

 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 7841.

 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 https://www.rfc-editor.org/info/rfc8909.

Copyright Notice

 Copyright (c) 2020 IETF Trust and the persons identified as the
 document authors.  All rights reserved.

 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (https://trustee.ietf.org/license-info) in effect on the date of
 publication of this document.  Please review these documents
 carefully, as they describe your rights and restrictions with respect
 to this document.  Code Components extracted from this document must
 include Simplified BSD License text as described in Section 4.e of
 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.

Table of Contents

 1.  Introduction
 2.  Terminology
 3.  Problem Scope
 4.  Conventions Used in This Document
   4.1.  Date and Time
 5.  Protocol Description
   5.1.  Root Element <deposit>
   5.2.  Rebuilding the Registry from Data Escrow Deposits
 6.  Formal Syntax
   6.1.  RDE Schema
 7.  Internationalization Considerations
 8.  IANA Considerations
 9.  Security Considerations
 10. Privacy Considerations
 11. Example of a Full Deposit
 12. Example of a Differential Deposit
 13. Example of an Incremental Deposit
 14. References
   14.1.  Normative References
   14.2.  Informative References
 Acknowledgments
 Author's Address

1. Introduction

 Registry Data Escrow (RDE) is the process by which a registry
 periodically submits data deposits to a third party called an escrow
 agent.  These deposits comprise the minimum data needed by a third
 party to resume operations if the registry cannot function and is
 unable or unwilling to facilitate an orderly transfer of service.
 For example, for a domain name registry or registrar, the data to be
 deposited would include all of the objects related to registered
 domain names, e.g., names, contacts, name servers.

 The goal of data escrow is higher resiliency of registration
 services, for the benefit of Internet users.  The beneficiaries of a
 registry are not just those registering information there but also
 the users of services relying on the registry data.

 In the context of domain name registries, registration data escrow is
 a requirement for generic Top-Level Domains (gTLDs) (e.g.,
 Specification 2 of the ICANN Base Registry Agreement; see
 [ICANN-GTLD-RA-20170731]), and some country code TLD (ccTLD) managers
 are also currently escrowing data.  There is also a similar
 requirement for ICANN-accredited domain registrars.

 This document specifies a format for data escrow deposits independent
 of the objects being escrowed.  An independent specification is
 required for each type of registry/set of objects that is expected to
 be escrowed.

 The format for data escrow deposits is specified using version 1.0 of
 the Extensible Markup Language (XML) as described in
 [W3C.REC-xml-20081126], and XML Schema notation as described in
 [W3C.REC-xmlschema-1-20041028] and [W3C.REC-xmlschema-2-20041028].

 Readers are advised to read Section 2 ("Terminology") carefully to
 understand the precise meanings of Differential and Incremental
 Deposits, as the definitions used in this document are different from
 the definitions typically used in the domain of data backups.

2. Terminology

 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
 "OPTIONAL" in this document are to be interpreted as described in
 BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
 capitals, as shown here.

 Deposit:  There are three kinds of deposits: Full, Differential, and
    Incremental.  For all three kinds of deposits, the universe of
    registry objects to be considered for data escrow is comprised of
    any objects required to offer the registry services.

 Differential Deposit:  A Differential Deposit contains data that
    reflects all transactions involving the database that were not
    reflected in the last previous Full, Incremental, or Differential
    Deposit, as the case may be.  Differential Deposit files will
    contain information from all database objects that were added,
    modified, or deleted since the previous deposit was completed as
    of its defined Timeline Watermark.

 Domain Name:  See the definition of "domain name" in [RFC8499].

 Escrow Agent:  An escrow agent is the organization designated by the
    registry or the third-party beneficiary to receive and guard data
    escrow deposits from the registry.

 Full Deposit:  A Full Deposit contains the registry data that
    reflects the current and complete registry database and will
    consist of data that reflects the state of the registry as of a
    defined Timeline Watermark for the deposit.

 Incremental Deposit:  An Incremental Deposit contains data that
    reflects all transactions involving the database that were not
    reflected in the last previous Full Deposit.  Incremental Deposit
    files will contain information from all database objects that were
    added, modified, or deleted since the previous Full Deposit was
    completed as of its defined Timeline Watermark.  If the Timeline
    Watermark of an Incremental Deposit were to cover the Timeline
    Watermark of another Incremental or Differential Deposit since the
    last Full Deposit (i.e., one or more Incremental or Differential
    Deposits exist for the period between the Timeline Watermark of a
    Full Deposit and an Incremental or Differential Deposit), the more
    recent deposit MUST contain all of the transactions of the earlier
    deposit.

 Registrar:  See the definition of "registrar" in [RFC8499].

 Registry:  See the definition of "registry" in [RFC8499].

 Third-Party Beneficiary:  A third-party beneficiary is the
    organization that, under extraordinary circumstances, would
    receive the escrow deposits the registry transferred to the escrow
    agent.  This organization could be a backup registry, registry
    regulator, contracting party of the registry, etc.

 Timeline Watermark:  The Timeline Watermark is the point in time on
    which to base the collecting of database objects for a deposit.
    Deposits are expected to be consistent with that point in time.

 Top-Level Domain (TLD):  See the definition of "Top-Level Domain" in
    [RFC8499].

3. Problem Scope

 In the past few years, the issue of registry continuity has been
 carefully considered in the gTLD and ccTLD spaces.  Various
 organizations have carried out risk analyses and developed business
 continuity plans to deal with those risks, should they materialize.

 One of the solutions considered and used, especially in the gTLD
 space, is Registry Data Escrow as a way to ensure the continuity of
 registry services in the extreme case of registry failure.

 So far, almost every registry that uses Registry Data Escrow has its
 own specification.  It is anticipated that more registries will be
 implementing escrow, especially with an increasing number of domain
 registries coming into service, adding complexity to this issue.

 It would seem beneficial to have a standardized specification for
 Registry Data Escrow that can be used by any registry to submit its
 deposits.

 While the domain name industry has been the main target for this
 specification, it has been designed to be as general as possible.

 Specifications covering the objects used by registration
 organizations shall identify the format and contents of the deposits
 a registry has to make, such that a different registry would be able
 to rebuild the registration services of the former, without its help,
 in a timely manner and with minimum disruption to its users.

 Since the details of the registration services provided vary from
 registry to registry, specifications covering the objects used by
 registration organizations shall provide mechanisms that allow
 extensibility to accommodate variations and extensions of the
 registration services.

 Given the requirement for confidentiality and the importance of
 accuracy of the information that is handled in order to offer
 registration services, parties using this specification shall define
 confidentiality and integrity mechanisms for handling the
 registration data.

 Specifications covering the objects used by registration
 organizations shall not include in the specification transient
 objects that can be recreated by the new registry, particularly those
 of delicate confidentiality, e.g., DNSSEC KSK/ZSK (Key Signing Key /
 Zone Signing Key) private keys.

 Details that are a matter of policy should be identified as such for
 the benefit of the implementers.

 Non-technical issues concerning data escrow, such as whether to
 escrow data and for what purposes the data may be used, are outside
 the scope of this document.

 Parties using this specification shall use a signaling mechanism to
 control the transmission, reception, and validation of data escrow
 deposits.  The definition of such a signaling mechanism is outside
 the scope of this document.

4. Conventions Used in This Document

 The XML namespace prefix "rde" is used for the namespace
 "urn:ietf:params:xml:ns:rde-1.0", but implementations MUST NOT depend
 on it; instead, they should employ a proper namespace-aware XML
 parser and serializer to interpret and output the XML documents.

 The XML namespace prefixes "rdeObj1" and "rdeObj2", with the
 corresponding namespaces "urn:example:params:xml:ns:rdeObj1-1.0" and
 "urn:example:params:xml:ns:rdeObj2-1.0", are used as example data
 escrow objects.

4.1. Date and Time

 Numerous fields indicate "dates", such as the creation and expiry
 dates for objects.  These fields SHALL contain timestamps indicating
 the date and time in UTC, specified in Internet Date/Time Format (see
 [RFC3339], Section 5.6) with the time-offset parameter specified as
 "Z".

5. Protocol Description

 The format for data escrow deposits as produced by a registry is
 defined below.  The deposits are represented in XML (Section 6).
 Only the format of the objects deposited is defined.  This document
 does not prescribe the method used to transfer such deposits between
 the registry and the escrow agent or vice versa.

 The protocol intends to be object agnostic, allowing the "overload"
 of abstract elements using the "substitutionGroup" attribute
 [W3C.REC-xmlschema-1-20041028] of the XML Schema element to define
 the actual elements of an object to be escrowed.

 The specification for each object to be escrowed MUST declare the
 identifier to be used to reference the object to be deleted or added/
 modified.

5.1. Root Element <deposit>

 The container or root element for a Registry Data Escrow deposit is
 <deposit>.

 The <deposit> element contains the following attributes:

A REQUIRED "type" attribute that is used to identify the kind of

deposit:

FULL: Full.

INCR: Incremental.

DIFF: Differential.

A REQUIRED "id" attribute that is used to uniquely identify the

escrow deposit. Each registry is responsible for maintaining its

    own escrow deposits' identifier space to ensure uniqueness.

A "prevId" attribute that can be used to identify the previous

Incremental, Differential, or Full Deposit. This attribute is

    REQUIRED in Differential Deposits ("DIFF" type), is OPTIONAL in
    Incremental Deposits ("INCR" type), and is not used in Full
    Deposits ("FULL" type).

An OPTIONAL "resend" attribute that is incremented each time the

escrow deposit failed the verification procedure at the receiving

    party and a new escrow deposit needs to be generated by the
    registry for that specific date.  The first time a deposit is
    generated, the attribute either (1) is omitted or (2) MUST be "0".
    If a deposit needs to be generated again, the attribute MUST be
    set to "1", and so on.

 The <deposit> element contains the following child elements:

5.1.1. Child <watermark> Element

 A REQUIRED <watermark> element contains the date-time [RFC3339]
 corresponding to the Timeline Watermark of the deposit.

5.1.2. Child <rdeMenu> Element

 This element contains auxiliary information regarding the data escrow
 deposit.

 A REQUIRED <rdeMenu> element contains the following child elements:

A REQUIRED <version> element that identifies the RDE protocol

version. This value MUST be 1.0.

One or more <objURI> elements that contain namespace URIs

representing the <contents> and <deletes> element objects.

5.1.3. Child <deletes> Element

 For Differential Deposits, this element contains the list of objects
 that have been deleted since the previous deposit of any type.  For
 Incremental Deposits, this element contains the list of objects that
 have been deleted since the previous Full Deposit.

 This section of the deposit MUST NOT be present in Full Deposits.

5.1.4. Child <contents> Element

 For Full Deposits, this element contains all objects.  For
 Differential Deposits, this element contains the list of objects that
 have been added or modified since the previous deposit of any type.
 For Incremental Deposits, this element contains the list of objects
 that have been added or modified since the previous Full Deposit.

5.2. Rebuilding the Registry from Data Escrow Deposits

 When applying Incremental or Differential Deposits (when rebuilding
 the registry from data escrow deposits), the relative order of the
 <deletes> and <contents> elements is important because dependencies
 may exist between the objects.  All of the <deletes> elements MUST be
 applied first, in the order in which they appear.  All of the
 <contents> elements MUST be applied next, in the order in which they
 appear.

 If an object is present in the <contents> or <deletes> section of
 several deposits (e.g., Full and Differential), the registry data
 from the latest deposit (as defined by the Timeline Watermark) SHOULD
 be used when rebuilding the registry.  An object SHOULD NOT exist
 multiple times in either the <contents> or <deletes> elements in a
 single deposit.

 When rebuilding a registry, the <deletes> section MUST be ignored if
 present in a Full Deposit.

6. Formal Syntax

 RDE is specified in XML Schema notation.  The formal syntax presented
 here is a complete schema representation of RDE suitable for
 automated validation of RDE XML instances.

 The <CODE BEGINS> and <CODE ENDS> tags are not part of the schema;
 they are used to note the beginning and ending of the schema for URI
 registration purposes.

6.1. RDE Schema

 <CODE BEGINS>
 <?xml version="1.0" encoding="UTF-8"?>
 <schema targetNamespace="urn:ietf:params:xml:ns:rde-1.0"
   xmlns:rde="urn:ietf:params:xml:ns:rde-1.0"
   xmlns="http://www.w3.org/2001/XMLSchema"
   elementFormDefault="qualified">

   <annotation>
     <documentation>
       Registry Data Escrow schema
     </documentation>
   </annotation>

   <!-- Root element -->
   <element name="deposit" type="rde:escrowDepositType"/>

   <!-- RDE types -->
   <complexType name="escrowDepositType">
     <sequence>
       <element name="watermark" type="dateTime"/>
       <element name="rdeMenu" type="rde:rdeMenuType"/>
       <element name="deletes" type="rde:deletesType" minOccurs="0"/>
       <element name="contents" type="rde:contentsType"
         minOccurs="0"/>
     </sequence>
     <attribute name="type" type="rde:depositTypeType"
       use="required"/>
     <attribute name="id" type="rde:depositIdType" use="required"/>
     <attribute name="prevId" type="rde:depositIdType"/>
     <attribute name="resend" type="unsignedShort" default="0"/>
   </complexType>

   <!-- Menu type -->
   <complexType name="rdeMenuType">
     <sequence>
       <element name="version" type="rde:versionType"/>
       <element name="objURI" type="anyURI" maxOccurs="unbounded"/>
     </sequence>
   </complexType>

   <!-- Deletes type -->
   <complexType name="deletesType">
     <sequence minOccurs="0" maxOccurs="unbounded">
       <element ref="rde:delete"/>
     </sequence>
   </complexType>

   <element name="delete" type="rde:deleteType" abstract="true"/>
   <complexType name="deleteType">
     <complexContent>
       <restriction base="anyType"/>
     </complexContent>
   </complexType>

   <!-- Contents type -->
   <complexType name="contentsType">
     <sequence minOccurs="0" maxOccurs="unbounded">
       <element ref="rde:content"/>
     </sequence>
   </complexType>

   <element name="content" type="rde:contentType" abstract="true"/>
   <complexType name="contentType">
     <complexContent>
       <restriction base="anyType"/>
     </complexContent>
   </complexType>

   <!-- Type of deposit -->
   <simpleType name="depositTypeType">
     <restriction base="token">
       <enumeration value="FULL"/>
       <enumeration value="INCR"/>
       <enumeration value="DIFF"/>
     </restriction>
   </simpleType>

   <!-- Deposit identifier type -->
   <simpleType name="depositIdType">
     <restriction base="token">
       <pattern value="\w{1,13}"/>
     </restriction>
   </simpleType>

   <!-- A RDE version number is a dotted pair of decimal numbers -->
   <simpleType name="versionType">
     <restriction base="token">
       <pattern value="[1-9]+\.[0-9]+"/>
       <enumeration value="1.0"/>
     </restriction>
   </simpleType>

 </schema>
 <CODE ENDS>

7. Internationalization Considerations

 Data escrow deposits are represented in XML, which provides native
 support for encoding information using the Unicode character set and
 its more compact representations, including UTF-8.  Conformant XML
 processors recognize both UTF-8 and UTF-16.  Though XML includes
 provisions to identify and use other character encodings through the
 use of an "encoding" attribute in an <?xml?> declaration, the use of
 UTF-8 is RECOMMENDED.

8. IANA Considerations

 This document uses URNs to describe XML namespaces and XML schemas
 conforming to a registry mechanism described in [RFC3688].  Two URI
 assignments have been registered by the IANA.

 Registration for the RDE namespace:

 URI:  urn:ietf:params:xml:ns:rde-1.0
 Registrant Contact:  IESG
 XML:  None.  Namespace URIs do not represent an XML specification.

 Registration for the RDE XML schema:

 URI:  urn:ietf:params:xml:schema:rde-1.0
 Registrant Contact:  IESG

 See Section 6 ("Formal Syntax") of this document.

9. Security Considerations

 This specification does not define the security mechanisms to be used
 in the transmission of the data escrow deposits, since it only
 specifies the minimum necessary to enable the rebuilding of a
 registry from deposits without intervention from the original
 registry.

 Depending on local policies, some elements -- or, most likely, the
 whole deposit -- will be considered confidential.  As such, the
 parties SHOULD take all necessary precautions, such as encrypting the
 data at rest and in transit to avoid inadvertent disclosure of
 private data.  Regardless of the precautions taken by the parties
 regarding data at rest and in transit, authentication credentials
 MUST NOT be escrowed.

 Authentication of the parties passing data escrow deposit files is
 also of the utmost importance.  The escrow agent MUST properly
 authenticate the identity of the registry before accepting data
 escrow deposits.  Similarly, the registry MUST authenticate the
 identity of the escrow agent before submitting any data.

 Additionally, the registry and the escrow agent MUST use integrity-
 checking mechanisms to ensure that the data transmitted is what the
 source intended.  Validation of the contents by the escrow agent is
 RECOMMENDED to ensure not only that the file was transmitted
 correctly from the registry but also that the contents are
 "meaningful".

    |  Note: If Transport Layer Security (TLS) is used when providing
    |  an escrow service, the recommendations in [RFC7525] MUST be
    |  implemented.

10. Privacy Considerations

 This specification defines a format that may be used to escrow
 personal data.  The process of data escrow is governed by a legal
 document agreed upon by the parties, and such a legal document must
 ensure that privacy-sensitive and/or personal data receives the
 required protection.

11. Example of a Full Deposit

 Example of a Full Deposit with the two example objects rdeObj1 and
 rdeObj2:

 <?xml version="1.0" encoding="UTF-8"?>
 <rde:deposit
   xmlns:rde="urn:ietf:params:xml:ns:rde-1.0"
   xmlns:rdeObj1="urn:example:params:xml:ns:rdeObj1-1.0"
   xmlns:rdeObj2="urn:example:params:xml:ns:rdeObj2-1.0"
   type="FULL"
   id="20191018001">
   <rde:watermark>2019-10-17T23:59:59Z</rde:watermark>
   <rde:rdeMenu>
     <rde:version>1.0</rde:version>
     <rde:objURI>urn:example:params:xml:ns:rdeObj1-1.0</rde:objURI>
     <rde:objURI>urn:example:params:xml:ns:rdeObj2-1.0</rde:objURI>
   </rde:rdeMenu>
   <rde:contents>
     <rdeObj1:rdeObj1>
       <rdeObj1:name>EXAMPLE</rdeObj1:name>
     </rdeObj1:rdeObj1>
     <rdeObj2:rdeObj2>
       <rdeObj2:id>fsh8013-EXAMPLE</rdeObj2:id>
     </rdeObj2:rdeObj2>
   </rde:contents>
 </rde:deposit>

12. Example of a Differential Deposit

 Example of a Differential Deposit with the two example objects
 rdeObj1 and rdeObj2:

 <?xml version="1.0" encoding="UTF-8"?>
 <rde:deposit
   xmlns:rde="urn:ietf:params:xml:ns:rde-1.0"
   xmlns:rdeObj1="urn:example:params:xml:ns:rdeObj1-1.0"
   xmlns:rdeObj2="urn:example:params:xml:ns:rdeObj2-1.0"
   type="DIFF"
   id="20191019001" prevId="20191018001">
   <rde:watermark>2019-10-18T23:59:59Z</rde:watermark>
   <rde:rdeMenu>
     <rde:version>1.0</rde:version>
       <rde:objURI>urn:example:params:xml:ns:rdeObj1-1.0</rde:objURI>
       <rde:objURI>urn:example:params:xml:ns:rdeObj2-1.0</rde:objURI>
   </rde:rdeMenu>
   <rde:contents>
     <rdeObj1:rdeObj1>
       <rdeObj1:name>EXAMPLE2</rdeObj1:name>
     </rdeObj1:rdeObj1>
     <rdeObj2:rdeObj2>
       <rdeObj2:id>sh8014-EXAMPLE</rdeObj2:id>
     </rdeObj2:rdeObj2>
   </rde:contents>
 </rde:deposit>

13. Example of an Incremental Deposit

 Example of an Incremental Deposit with the two example objects
 rdeObj1 and rdeObj2:

 <?xml version="1.0" encoding="UTF-8"?>
 <rde:deposit
   xmlns:rde="urn:ietf:params:xml:ns:rde-1.0"
   xmlns:rdeObj1="urn:example:params:xml:ns:rdeObj1-1.0"
   xmlns:rdeObj2="urn:example:params:xml:ns:rdeObj2-1.0"
   type="INCR"
   id="20200317001" prevId="20200314001">
   <rde:watermark>2020-03-16T23:59:59Z</rde:watermark>
   <rde:rdeMenu>
     <rde:version>1.0</rde:version>
     <rde:objURI>urn:example:params:xml:ns:rdeObj1-1.0</rde:objURI>
     <rde:objURI>urn:example:params:xml:ns:rdeObj2-1.0</rde:objURI>
   </rde:rdeMenu>
   <rde:deletes>
     <rdeObj1:delete>
       <rdeObj1:name>EXAMPLE1</rdeObj1:name>
     </rdeObj1:delete>
     <rdeObj2:delete>
       <rdeObj2:id>fsh8013-EXAMPLE</rdeObj2:id>
     </rdeObj2:delete>
   </rde:deletes>
   <rde:contents>
     <rdeObj1:rdeObj1>
       <rdeObj1:name>EXAMPLE2</rdeObj1:name>
     </rdeObj1:rdeObj1>
     <rdeObj2:rdeObj2>
       <rdeObj2:id>sh8014-EXAMPLE</rdeObj2:id>
     </rdeObj2:rdeObj2>
   </rde:contents>
 </rde:deposit>

14. References

14.1. Normative References

 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119,
            DOI 10.17487/RFC2119, March 1997,
            <https://www.rfc-editor.org/info/rfc2119>.

 [RFC3339]  Klyne, G. and C. Newman, "Date and Time on the Internet:
            Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
            <https://www.rfc-editor.org/info/rfc3339>.

 [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
            2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
            May 2017, <https://www.rfc-editor.org/info/rfc8174>.

 [RFC8499]  Hoffman, P., Sullivan, A., and K. Fujiwara, "DNS
            Terminology", BCP 219, RFC 8499, DOI 10.17487/RFC8499,
            January 2019, <https://www.rfc-editor.org/info/rfc8499>.

 [W3C.REC-xml-20081126]
            Bray, T., Ed., Paoli, J., Ed., Sperberg-McQueen, C.M.,
            Ed., Maler, E., Ed., and F. Yergeau, Ed., "Extensible
            Markup Language (XML) 1.0 (Fifth Edition)", REC-xml-
            20081126, November 2008,
            <https://www.w3.org/TR/2008/REC-xml-20081126/>.

 [W3C.REC-xmlschema-1-20041028]
            Thompson, H.S., Ed., Beech, D., Ed., Maloney, M., Ed., and
            N. Mendelsohn, Ed., "XML Schema Part 1: Structures Second
            Edition", REC-xmlschema-1-20041028, October 2004,
            <https://www.w3.org/TR/2004/REC-xmlschema-1-20041028/>.

 [W3C.REC-xmlschema-2-20041028]
            Biron, P. V., Ed. and A. Malhotra, Ed., "XML Schema Part
            2: Datatypes Second Edition", REC-xmlschema-2-20041028,
            October 2004,
            <https://www.w3.org/TR/2004/REC-xmlschema-2-20041028/>.

14.2. Informative References

 [ICANN-GTLD-RA-20170731]
            ICANN, "Base Registry Agreement", 31 July 2017,
            <https://newgtlds.icann.org/sites/default/files/
            agreements/agreement-approved-31jul17-en.pdf>.

 [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
            DOI 10.17487/RFC3688, January 2004,
            <https://www.rfc-editor.org/info/rfc3688>.

 [RFC7525]  Sheffer, Y., Holz, R., and P. Saint-Andre,
            "Recommendations for Secure Use of Transport Layer
            Security (TLS) and Datagram Transport Layer Security
            (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
            2015, <https://www.rfc-editor.org/info/rfc7525>.

Acknowledgments

 Special suggestions that were incorporated into this document were
 provided by James Gould, Edward Lewis, Jaap Akkerhuis, Lawrence
 Conroy, Marc Groeneweg, Michael Young, Chris Wright, Patrick Mevzek,
 Stephen Morris, Scott Hollenbeck, Stephane Bortzmeyer, Warren Kumari,
 Paul Hoffman, Vika Mpisane, Bernie Hoeneisen, Jim Galvin, Andrew
 Sullivan, Hiro Hotta, Christopher Browne, Daniel Kalchev, David
 Conrad, James Mitchell, Francisco Obispo, Bhadresh Modi, and
 Alexander Mayrhofer.

 Shoji Noguchi and Francisco Arias participated as coauthors through
 version 07 of draft-arias-noguchi-registry-data-escrow (the precursor
 to this document) and provided invaluable support for this document.

Author's Address

 Gustavo Lozano
 Internet Corporation for Assigned Names and Numbers
 12025 Waterfront Drive, Suite 300
 Los Angeles, CA 90292
 United States of America

 Phone: +1.310.823.9358
 Email: gustavo.lozano@icann.org