Internet Engineering Task Force                                 S. Sheth
Internet-Draft                                                 A. Kaizer
Intended status: Informational                             Verisign Labs
Expires: 19 July 2025                                         B. Newbold
                                                            Bluesky, PBC
                                                              N. Johnson
                                                                ENS Labs
                                                         15 January 2025


     Integration of DNS Domain Names into Application Environments:
                     Motivations and Considerations
                     draft-sheth-dns-integration-03

Abstract

   This document reviews the motivations and considerations for
   integrating DNS domain names into an application environment and
   provides terminology to establish a shared understanding of what a
   DNS integration may entail.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 19 July 2025.

Copyright Notice

   Copyright (c) 2025 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



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   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Intended Audience . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Motivations to use Global DNS Domain Names  . . . . . . . . .   4
     3.1.  Global Consistency and Universal Acceptance . . . . . . .   4
     3.2.  Stability . . . . . . . . . . . . . . . . . . . . . . . .   5
     3.3.  Flexibility . . . . . . . . . . . . . . . . . . . . . . .   5
     3.4.  Verifiability . . . . . . . . . . . . . . . . . . . . . .   5
     3.5.  Reputation and Brand  . . . . . . . . . . . . . . . . . .   5
   4.  Qualities of a DNS Integration  . . . . . . . . . . . . . . .   6
     4.1.  Domain Name Lifecycle . . . . . . . . . . . . . . . . . .   6
     4.2.  Domain Control Validation . . . . . . . . . . . . . . . .   6
     4.3.  Completeness  . . . . . . . . . . . . . . . . . . . . . .   7
     4.4.  Synchronization . . . . . . . . . . . . . . . . . . . . .   7
     4.5.  DNS Protocol Evolution  . . . . . . . . . . . . . . . . .   8
     4.6.  Identifier Attribution  . . . . . . . . . . . . . . . . .   8
     4.7.  Variety of DNS Management User Interfaces . . . . . . . .   8
     4.8.  DNS Record Support  . . . . . . . . . . . . . . . . . . .   9
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   7.  Informative References  . . . . . . . . . . . . . . . . . . .   9
   Appendix A.  Integration Lessons Learned  . . . . . . . . . . . .  10
     A.1.  Bluesky and AT Protocol . . . . . . . . . . . . . . . . .  10
     A.2.  Ethereum Name Service . . . . . . . . . . . . . . . . . .  12
   Appendix B.  Change Log . . . . . . . . . . . . . . . . . . . . .  12
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   This document reviews motivations and considerations for integrating
   a domain name from the global DNS into an application environment.
   Section 2.1 of [RFC1034] notes that the term "domain name" has a
   varied history, however this document is targeted at domain names
   from the "global DNS" as defined in [RFC2826] and [RFC9499], i.e.,
   the DNS namespace as managed and governed by ICANN's multistakeholder
   model.  As such, other systems that use a domain name-based syntax
   that are not part of the global DNS are not the focus although such
   systems may find portions of this document applicable.  The rest of
   this document proceeds under this framing.





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   Domain names from the global DNS have long been used as identifiers
   in applications.  In the early days, domain names were associated
   with Teletype Network (TELNET) hosts, File Transfer Protocol (FTP)
   servers, and email services.  Later, domain names were adopted for
   web browsing.  More recently, blockchain applications, decentralized
   protocols, and social media platforms have emerged as new use cases
   for domain names.  How a domain name is enabled for use as an
   identifier in each of these applications is known as a DNS
   integration.

   Given the ever-increasing number of application environments using or
   proposing their own DNS integrations, there is a need to raise
   awareness about considerations that such applications should consider
   in order to provide a "responsible" DNS integration.  A responsible
   DNS integration can be defined as one that allows a domain name to be
   used within an application environment in a way that provides a
   consistent user experience (unique identifier across environments)
   and extends the security, stability, and resiliency of the global
   DNS.

   Failure to account for the considerations described in this document
   may result in user confusion, name collisions between an application
   and the global DNS, or other security related concerns.  For example,
   an application providing a DNS integration that does not account for
   the domain name lifecycle will become mis-aligned with the global DNS
   if an integrated domain name is deleted or is transferred.  At that
   point, the domain name will be controlled by different parties in the
   global DNS and the application providing a DNS integration -- an
   undesirable outcome.

   In support of the development of responsible DNS integrations, this
   document reviews qualities and considerations that DNS integrations
   should account for.  Applications providing a DNS integration may use
   this document as a checklist that, if accounted for, can decrease
   outcomes that could negatively impact the security of the application
   and the global DNS.

1.1.  Intended Audience

   This document is for everyone who wants a globally unique naming
   system that avoids user confusion, i.e., the global DNS as described
   in [RFC2826].

   This document can best be realized by applications that provide DNS
   integrations.  There are many ways to provide a DNS integration,
   including but not limited to:





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   *  Integrations that leverage domain control validation as described
      in [I-D.ietf-dnsop-domain-verification-techniques]
   *  Integrations that store data associated with the domain name in
      the domain name's zone
   *  Integrations that store data associated with the domain name
      outside of the DNS, e.g., on a well-known endpoint of a web server
      or decentralized storage platform

   Given the above, any application providing an integration using these
   or similar approaches is the intended audience for this document.

2.  Terminology

   This document uses the terminology from [RFC9499] as a baseline.
   Additional terms applicable to DNS integrations are provided here in
   alphabetical order:

   *  Application environment: An application, platform, or protocol
   *  DNS integration: How a domain name is enabled for use as an
      identifier in an application environment
   *  Responsible DNS integration: Takes into account qualities and
      considerations that provide a consistent user experience and
      extends the security, stability, and resiliency of the global DNS
   *  Synchronization: The property that an object integrated into an
      application environment aligns with its state in its original
      environment

3.  Motivations to use Global DNS Domain Names

   Application environments might be motivated to integrate with the
   global DNS for various reasons: global consistency, universal
   acceptance, human-readable identifiers, stability, flexibility,
   verifiability, and to utilize the reputation registrants may have
   already developed around their use of a domain name.

   This section briefly describes these reasons, however additional
   motivations likely exist.  References to specific examples are used
   to illustrate the general point, while the appendix contains case
   studies that describe specific integrations.

3.1.  Global Consistency and Universal Acceptance

   Application environments might integrate domain names because they
   want globally consistent, human-friendly identifiers that have (near)
   universal acceptance throughout deployed software and infrastructure.
   Challenges can occur in namespaces that lack (near) universal
   acceptance, such as those described in ICANN's [OCTO-034].




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3.2.  Stability

   The global DNS has developed a technical, social, and policy
   infrastructure over decades that has led to a stable and reliable
   naming and resolution system.  Section 4.8 of [RFC9518] also notes
   that an application environment may prefer to avoid technical and
   governance complications related to implementing a naming function of
   its own by leveraging the existing stability of the DNS protocol.

3.3.  Flexibility

   The global DNS provides the administrator of a namespace technical
   flexibility for how to use it.  Examples of this flexibility include
   which DNS provider to use (including the option to self-host), which
   DNS records to set, and which subdomains to delegate (if any).

   One specific example of this flexibility is how Bluesky can issue
   subdomains as a user's handle on Bluesky.  When users sign up for a
   Bluesky account, they can opt to be given a handle under the
   *.bsky.social domain space.  Bluesky can provide this flexibility
   because the DNS allows for it.

3.4.  Verifiability

   DNS provides cryptographic verifiability of DNS zone data through
   DNSSEC.  DNSSEC is the standards-defined way of digitally signing and
   verifying DNS data.  For some application environments, such as those
   being used for payment use cases, this verifiability might be
   important to ensuring that funds are being referred to the
   appropriate target.

   One example of verifiability is how Ethereum Name Service uses DNSSEC
   data to validate DNS resource records associated with the given
   domain name.  Once validated, these records are used by Ethereum Name
   Service clients to support Ethereum Name Service use cases, such as
   routing payments.

3.5.  Reputation and Brand

   Individuals and institutions that have registered a domain name can
   build a reputation around that domain name over time.  Domain names
   may be considered as part of a brand, e.g., when the domain name is
   also the name of the company.  In such cases, enabling the registrant
   to expand the use of their existing domain name into new application
   environments adds an alternative to creating separate identities on
   each platform as they can continue to build or leverage their
   reputation and brand around their existing domain name.




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   Additionally, if a user is familiar with a domain name and sees that
   domain name in a well designed DNS integration, then the user might
   have a reasonable assurance that it is the same domain name as they
   can resolve in the global DNS, e.g., via web browsing.  This can
   benefit the integrating application environment as users who identify
   familiar domain names can quickly bootstrap their existing
   familiarity into this new context.

4.  Qualities of a DNS Integration

   This section provides qualities that a DNS integration should account
   for in their specification design.  Failure to account for these
   might lead to negative outcomes, such as user confusion or name
   collisions that could provide complications to both the global DNS
   and application environments using a given DNS integration.  The
   exact risks depend on the context and design of the integration and
   are out of scope for this document.

4.1.  Domain Name Lifecycle

   A DNS integration should account for the domain name lifecycle
   events.  Some examples of lifecycle events include expiration, change
   in DNSSEC status, or technical changes that affect the integration
   such as the removal of an expected resource record.  Such lifecycle
   events might result in a change of control or status of the domain
   name compared to when it was originally integrated that could require
   one of the parties involved in the DNS integration to take some
   action to stay synchronized with the state of the domain name in the
   global DNS.

   Failure to account for the domain name lifecycle might result in a
   DNS integration allowing users other than the current registrant of
   the domain name to control the domain name in the integration which
   could lead to confusion.

4.2.  Domain Control Validation

   A DNS integration should implement validation checks to ensure only
   the DNS registrant or an authorized party associated with the domain
   name can establish the integration.  Some examples of domain control
   validation include storing data in DNS
   [I-D.ietf-dnsop-domain-verification-techniques] or storing evidence
   on a server referenced by a domain name, e.g., at a well-known
   endpoint as described in [RFC8615].







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   Failure to perform validation might result in a DNS integration
   allowing users other than the current registrant of the domain name
   to control the domain name in the integration which could be
   confusing.  This could lead to a security risk which may break end
   user trust.

4.3.  Completeness

   A DNS integration should allow any domain name that meets the
   integration's technical criteria to be integrated.  Not doing so
   excludes domain names from participation for non-technical reasons,
   which could lead to registrant confusion if they are not able to
   associate their domain name.

   DNS integrations should also be aware that global DNS domain names
   are not limited to ASCII characters, e.g., as described in [RFC5890].
   Failure to account for such domain names may lead to inadvertent
   exclusion which could also lead to registrant confusion.

4.4.  Synchronization

   A DNS integration should provide mechanisms to handle cases where an
   integrated domain name is no longer synchronized.  How often to
   execute such mechanisms will vary by DNS integration and the use
   cases supported.  For example, a DNS integration that supports
   financial use cases may check more often than a DNS integration that
   shows a verification of domain control badge on a social media
   profile.

   In general, the entity providing the DNS integration is primarily
   responsible for ensuring synchronization with the global DNS.  A DNS
   integration can allow other users to invoke one or more mechanisms,
   but this should not be solely relied upon as there are no guarantees
   that users will do so.  For example, if a domain name expires the
   registrant that originally interacted with the DNS integration may
   not be interested, aware, or available to invoke the mechanisms to
   remove the domain name.

   A designer of a DNS integration should also be cognizant that
   executing these mechanisms too frequently may result in rate
   limiting.  This may also occur if multiple integrated domain names
   share the same infrastructure which increases the potential that rate
   limits would be triggered.  Consequently, a DNS integration should
   account for this potential in their mechanisms.







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4.5.  DNS Protocol Evolution

   A designer of a DNS integration should be aware that the DNS protocol
   will evolve over time and such evolutions might impact their DNS
   integration.  For example, DNSSEC algorithms have changed over time
   as new algorithms are added, and existing algorithms are deprecated.
   Failure to account for such changes might pose a security risk, lead
   to user confusion, or cause a lack of interoperability with the
   current state of the global DNS.

4.6.  Identifier Attribution

   A designer of a DNS integration should not assume a domain name is a
   persistent identifier that always associates to the same registrant.
   Domain names may be deleted and re-registered or be transferred,
   which might result in the previous registrant no longer being
   associated with the domain name.  DNS integrations should account for
   such changes in control to avoid potential confusion, e.g., content
   being mis-attributed to the current registrant that belonged to a
   previous registrant.

   Additionally, domain names may be exposed to temporary interruptions
   such as system downtime, DNS hijacking, or web server compromise.
   Such events may unexpectedly change who can utilize the domain name
   or impact the ability of a DNS integration from checking the status
   of the domain name.  DNS integrations should have mechanisms in place
   to handle and recover from such issues, including allowing a
   registrant to re-integrate the domain name.

4.7.  Variety of DNS Management User Interfaces

   A DNS integration might request a user follow certain actions to
   enable the integration.  For example, a TXT record might need to be
   set or DNSSEC might need to be configured.  However, each DNS
   management user interface might expose how to achieve the required
   actions in different ways.  This introduces friction to the
   integration process as the user might only know what they need to do
   -- e.g., add a TXT record -- but not necessarily how to do it.
   Integrations might provide advice for how to perform such actions for
   some interfaces, but it is not feasible to do so for all.











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4.8.  DNS Record Support

   A DNS integration might utilize certain record types but these types
   might not be widely supported.  For example, new DNS record types
   will take time to be rolled out to DNS providers or a DNS provider
   might opt not to support a particular record type.  In such cases, a
   registrant would need to change to a new DNS provider that could
   support the required record type.

   Some DNS resolvers might fail when encountering new or unexpected
   record types.  In such cases, a different resolver would need to be
   utilized or the integration would need to directly handle resolution
   to ensure reliable access to the data stored in the DNS zone.

5.  IANA Considerations

   This document has no IANA actions.

6.  Security Considerations

   This document does not introduce new protocol artifacts with security
   considerations, however, DNS integrations should account for general
   DNS related issues including confusable characters such as those
   discussed in Section 4.4 of [RFC5890] and resource capacity
   considerations.

   Resource capacity in a DNS integration impacts who is capable of
   performing the necessary steps to participate in or validate the
   integration.  For example, if an integration requires DNSSEC then
   some clients might not be able to perform the necessary cryptographic
   operations on their own such as IoT devices or human users performing
   manual validation.  DNS integrations should be cognizant of this
   potential gap in capabilities and how it could impact their DNS
   integration.

   Minimizing conflicts between the global DNS and applications that
   integrate with the global DNS is one of the goals of this document.
   While all sources of potential conflict cannot be enumerated, this
   effort should improve the security posture of both the global DNS and
   integrating applications through highlighting considerations to
   account for when providing a DNS integration.

7.  Informative References

   [I-D.ietf-dnsop-domain-verification-techniques]
              Sahib, S. K., Huque, S., Wouters, P., and E. Nygren,
              "Domain Control Validation using DNS", Work in Progress,
              Internet-Draft, draft-ietf-dnsop-domain-verification-



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              techniques-04, 3 March 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-dnsop-
              domain-verification-techniques-04>.

   [OCTO-034] Durand, A. D., "Challenges with Alternative Name Systems",
              27 April 2022,
              <https://www.icann.org/en/system/files/files/octo-
              034-27apr22-en.pdf>.

   [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",
              STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987,
              <https://www.rfc-editor.org/info/rfc1034>.

   [RFC2826]  IAB, "IAB Technical Comment on the Unique DNS Root",
              RFC 2826, DOI 10.17487/RFC2826, May 2000,
              <https://www.rfc-editor.org/info/rfc2826>.

   [RFC5890]  Klensin, J., "Internationalized Domain Names for
              Applications (IDNA): Definitions and Document Framework",
              RFC 5890, DOI 10.17487/RFC5890, August 2010,
              <https://www.rfc-editor.org/info/rfc5890>.

   [RFC8615]  Nottingham, M., "Well-Known Uniform Resource Identifiers
              (URIs)", RFC 8615, DOI 10.17487/RFC8615, May 2019,
              <https://www.rfc-editor.org/info/rfc8615>.

   [RFC9499]  Hoffman, P. and K. Fujiwara, "DNS Terminology", BCP 219,
              RFC 9499, DOI 10.17487/RFC9499, March 2024,
              <https://www.rfc-editor.org/info/rfc9499>.

   [RFC9518]  Nottingham, M., "Centralization, Decentralization, and
              Internet Standards", RFC 9518, DOI 10.17487/RFC9518,
              December 2023, <https://www.rfc-editor.org/info/rfc9518>.

Appendix A.  Integration Lessons Learned

A.1.  Bluesky and AT Protocol

   Bluesky is a social media application built on the atproto (AT
   Protocol) network.  In atproto, account identities are rooted in the
   Decentralized Identifier (DID) system, a W3C standard.  Most DIDs are
   not human readable, so every account is also associated with a domain
   name, referred to as a "handle".  Handles are for display only: they
   are not used in persistent references (URIs), and can change any time
   without breaking social graph connections.  The handle/DID
   relationship must be verified bi-directionally, and DNS TXT records
   are one mechanism to verify the handle-to-DID direction.  Bluesky
   handles are a DNS Integration.



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   DNS was chosen as the handle namespace partially for technical
   maturity, efficiency, and cost reasons.  Registering a new handle
   needed to be fast (second-level latency), zero-cost, and reliable
   (near-zero downtime).  DNS meets all of these requirements.  The
   atproto network is design to accommodate billions of accounts, and
   DNS has also been shown to scale to hundreds of millions of
   registered domains without significant infrastructure burden.
   Service providers can use sub-domains as handles, and allocate them
   in large numbers even more efficiently.

   Bluesky is a small young company building a novel network protocol.
   DNS is a mature and broadly adopted technology, meaning developers
   are already familiar with it and have software implementations and
   infrastructure at hand.  The system is financially sustainable with a
   international multi-stakeholder governance structure, which means
   developers can build on it with confidence.

   DNS is global, distributed, and consistent which are important for a
   distributed network.  Independent service providers and software
   clients see the same view of the domain system, which means that end
   users will have a coherent experience regardless of provider or
   client.

   Domain names are well established in society.  Domain names are
   conceptually familiar and recognizable to most network users.
   Policies, legal precedent, and dispute resolution procedures are
   mature across many jurisdictions.  These help address the perential
   challenges of impersonation and trademark disputes.  In particular,
   many culturally relevant institutions and individuals already have
   domain names with an established reputation.  The flexibility of DNS
   allows those existing domains to be reused in a new context.

   To maximize these benefits, it is important that handle validation is
   consistent and reproducible by any party.  Any valid domain name
   (hostname) can be used as a handle and that all handles are valid
   globally resolvable domain names.  This ensures that every network
   service can resolve any handle in the network, without requiring
   special DNS software.  Use of the TXT record type has broad support
   in both client software and in DNS management interfaces.  Limited
   use of caching helps reduce breakage due to short network service
   downtimes, while still ensuring that handle validity lifetime is tied
   to domain registration lifetime.  In other words, changes in domain
   control are reflected in changes on handle validity within a
   reasonable time window, reducing the chance of misattribution.  The
   atproto handle specification text largely defers to IETF DNS
   standards, with the goal of maintaining compatibility as norms and
   best practices evolve over time.




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A.2.  Ethereum Name Service

   ENS integrates DNS names to provide a unified namespace across
   blockchain and traditional applications.  This expands ENS's
   usefulness by incorporating the millions of existing DNS names into
   the system, allowing people to use familiar identifiers that are
   already associated with their organization.

   The primary challenges have revolved around reliably identifying
   public suffixes, and identifying the authorized user for a domain.
   Early versions of the integration made unfounded assumptions, such as
   the ownership of nic.tld form domains.  This draft will help future
   implementers avoid such pitfalls.

Appendix B.  Change Log

      00: Initial draft of the document.

      01: Change to informational based on feedback received during IETF
      120 conversations.

      02: Add the Bluesky section and update based on further feedback
      from the DNSOP community.

      03: Generalized introduction text to focus on challenges and
      considerations, added ENS section.

Acknowledgements

   The authors would like to acknowledge the following individuals for
   their contributions to this document: TBD.

Authors' Addresses

   S. Sheth
   Verisign Labs
   12061 Bluemont Way
   Reston
   Email: ssheth@verisign.com
   URI:   https://www.verisignlabs.com/


   A. Kaizer
   Verisign Labs
   12061 Bluemont Way
   Reston
   Email: akaizer@verisign.com
   URI:   https://www.verisignlabs.com/



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   B. Newbold
   Bluesky, PBC
   Email: bryan@blueskyweb.xyz
   URI:   https://bsky.social/about


   N. Johnson
   ENS Labs
   Email: nick@ens.domains










































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