Musings on Digital Identity

Category: Claims Page 1 of 12

COSE “typ” (type) Header Parameter Specification in RFC Editor Queue

IETF logoI’m pleased to report that the COSE “typ” (type) Header Parameter Specification has been approved by the IESG and is now in the RFC Editor queue.

The version approved by the IESG and sent to the RFC Editor is:

It joins CBOR Web Token (CWT) Claims in COSE Headers in the RFC Editor queue. Because of the reference to this spec by CWT Claims in Headers, they form a cluster, and therefore will become RFCs at the same time.

Eight Specifications Published in Preparation for IETF 119

IETF logoMy co-authors and I published updated versions of eight specifications in preparation for IETF 119 in Brisbane. The specifications span three working groups: JOSE, COSE, and OAuth. The updated specifications and outcomes when discussed at IETF 119 are as follows.

1, 2, & 3: JSON Web Proof, JSON Proof Algorithms, and JSON Proof Token. Updates were:

  • Normatively defined header parameters used
  • Populated IANA Considerations sections
  • Allowed proof representations to contain multiple base64url-encoded parts
  • Specified representation of zero-length disclosed payloads
  • Added Terminology sections
  • Updated to use draft-irtf-cfrg-bbs-signatures-05
  • Updated to use draft-ietf-cose-bls-key-representations-04
  • More and better examples
  • Improvements resulting from a full proofreading

Continued reviews and feedback from implementations are requested.

4: Fully-Specified Algorithms for JOSE and COSE. Updates were:

  • Published initial working group document following adoption
  • Added text on fully-specified computations using multiple algorithms
  • Added text on KEMs and encapsulated keys
  • Updated instructions to the designated experts

It was agreed during the JOSE meeting to describe what fully-specified algorithms for ECDH would look like, for consideration by the working group.

5: OAuth 2.0 Protected Resource Metadata. Updates were:

  • Switched from concatenating .well-known to the end of the resource identifier to inserting it between the host and path components of it
  • Have WWW-Authenticate return resource_metadata URL rather than resource identifier

It was decided to start working group last call during the OAuth meeting.

6: COSE “typ” (type) Header Parameter. Updates were:

  • Added language about media type parameters
  • Addressed working group last call comments
  • Changed requested assignment from 14 to 16 due to conflict with a new assignment
  • Addressed GENART, OPSDIR, and SECDIR review comments

This document is scheduled for the April 4, 2024 IESG telechat.

7: Barreto-Lynn-Scott Elliptic Curve Key Representations for JOSE and COSE. Updates were:

  • Changed to use key type EC for JOSE and equivalent EC2 for COSE for uncompressed key representations
  • Changed identifier spellings from “Bls” to “BLS”, since these letters are people’s initials

We received feedback to not add compressed key representations to the draft.

8: Use of Hybrid Public-Key Encryption (HPKE) with JavaScript Object Signing and Encryption (JOSE). Updates were:

It was decided to start a working group call for adoption during the JOSE meeting.

Thanks to all who contributed to the progress made on these specifications, both before and during IETF 119!

COSE “typ” (type) Header Parameter Specification Addressing IETF Last Call Feedback

IETF logoOrie Steele and I have updated the COSE “typ” (type) Header Parameter Specification to address feedback received during IETF Last Call. No normative changes were made.

Thanks to those that reviewed the specification!

The specification is available at:

Besides the spec being useful on its own, it’s worth noting that the CBOR Web Token (CWT) Claims in COSE Headers specification references this spec, and so won’t exit the RFC Editor queue as an RFC until this one also does.

Celebrating Ten Years of OpenID Connect at the OpenID Summit Tokyo 2024

OpenID logoWe held the first of three planned tenth anniversary celebrations for the completion of OpenID Connect at the OpenID Summit Tokyo 2024. The four panelists were Nov Matake, Ryo Ito, Nat Sakimura, and myself. We shared our perspectives on what led to OpenID Connect, why it succeeded, and what lessons we learned along the way.

The most common refrain throughout our descriptions was the design philosophy to “Keep simple things simple”. I believe that three of the four of us cited it.

I recounted that we even had a thought experiment used to make the “Keep simple things simple” principle actionable in real time: the “Nov Matake Test”. As we considered new features, we’d ask ourselves “Would Nov want to add it to his implementation?” And “Is it simple enough that he could build it in a few hours?”

The other common thread was the criticality of interop testing and certification. We held five rounds of interop testing before finishing the specifications, with the specs being refined after each round based on the feedback received. The early developer feedback was priceless – much of it from Japan!

Our OpenID Connect 10th anniversary presentations were:

Thanks to the OpenID Foundation Japan for the thought-provoking and enjoyable OpenID Summit Tokyo 2024!

Panel in Tokyo

The Nov Matake Test

25 Years of OpenID

There Came Mike Jones

Ten Years of OpenID Connect and Looking to the Future

OpenID logoTen years ago today the drafts that would be approved as the final OpenID Connect specifications were published, as announced in my post Fourth and possibly last Release Candidates for final OpenID Connect specifications and Notice of 24 hour review period.

The adoption of OpenID Connect has exceeded our wildest expectations. The vast majority of federated signins to sites and applications today use OpenID Connect. Android, AOL, Apple, AT&T, Auth0, Deutsche Telekom, ForgeRock, Google, GrabTaxi, GSMA Mobile Connect, IBM, KDDI, Microsoft, NEC, NRI, NTT, Okta, Oracle, Orange, Ping Identity, Red Hat, Salesforce, Softbank, Symantec, T-Mobile, Telefónica, Verizon, Yahoo, and Yahoo! Japan, all use OpenID Connect, and that’s just the tip of the iceberg. While OpenID Connect is “plumbing” and not a consumer brand, it’s filling a need and doing it well.

It’s fitting that the second set of errata corrections to the OpenID Connect specifications were just approved, as described in the post Second Errata Set for OpenID Connect Specifications Approved. While we are proud of the quality of the final specifications, with 9 3/4 years of thousands of developers using and deploying the specifications, it’s unsurprising that issues would be found that needed clarification and correction.

The updated OpenID Connect specifications have just been submitted to the International Organization for Standardization (ISO) for Publicly Available Submission (PAS) status. Approved PAS submissions are published as ISO specifications. This will foster adoption in jurisdictions that require using standards that are published by organizations with international treaty status.

Celebrations of the tenth anniversary of the approval of OpenID Connect will occur worldwide in 2024. The first will be in Asia at the OpenID Summit Tokyo in January. The second will be in the Americas at Identiverse in May. The third will be in Europe at the European Identity and Cloud Conference in June. Join us at these events for the celebrations!

I can’t wait to see what the next decade brings for OpenID Connect!

BLS Key Representations for JOSE and COSE updated for IETF 118

IETF logoTobias Looker and I have published an updated Barreto-Lynn-Scott Elliptic Curve Key Representations for JOSE and COSE specification in preparation for IETF 118 in Prague. This one of suite of IETF and IRTF specifications, including BLS Signatures and JSON Web Proofs that are coming together to enable standards for the use of JSON-based and CBOR-based tokens utilizing zero-knowledge proofs.

The specification is available at:

CBOR Web Token (CWT) Claims in COSE Headers Draft Addressing IETF Last Call Comments

IETF logoTobias Looker and I have published an updated CBOR Web Token (CWT) Claims in COSE Headers specification that addresses the IETF Last Call (WGLC) comments received. Changes made were:

  • Added Privacy Consideration about unencrypted claims in header parameters.
  • Added Security Consideration about detached content.
  • Added Security Consideration about claims that are present both in the payload and the header of a CWT.
  • Changed requested IANA COSE Header Parameter assignment number from 13 to 15 due to subsequent assignments of 13 and 14.
  • Acknowledged last call reviewers.

The specification is available at:

The specification is scheduled for the IESG telechat on November 30, 2023.

JSON Web Proofs specifications updated in preparation for IETF 118

IETF logoDavid Waite and I have updated the “JSON Web Proof”, “JSON Proof Algorithms”, and “JSON Proof Token” specifications in preparation for presentation and discussions in the JOSE working group at IETF 118 in Prague. The primary updates were to align the BBS algorithm text and examples with the current CFRG BBS Signature Scheme draft. We also applied improvements suggested by Brent Zundel and Alberto Solavagione.

The specifications are available at:

Thanks to David Waite for doing the heavy lifting to update the BBS content. Thanks to MATTR for publishing their Pairing Cryptography software, which was used to generate the examples. And thanks to Alberto Solavagione for validating the specifications with his implementation.

CBOR Web Token (CWT) Claims in COSE Headers Draft Addressing Working Group Last Call Comments

IETF logoTobias Looker and I have published an updated CBOR Web Token (CWT) Claims in COSE Headers draft that addresses the COSE Working Group Last Call (WGLC) comments received. Changes made were:

  • Added Acknowledgements section.
  • Addressed WGLC feedback. Specifically…
  • Added statement about being able to use the header parameter in any COSE object.
  • Moved statement about verifying that claim values present in both the header and payload are identical from the Security Considerations to the body of the specification.

The specification is available at:

Touchstones Along My Identity Journey

EIC 2023 LogoI had the distinct honor of being invited to give a keynote talk at EIC 2023. The result was Touchstones Along My Identity Journey. My talk abstract was:

In 2005, Kim Cameron excitedly told me about digital identity and set my life on a course to “Build the Internet’s missing identity layer”. In this talk I’ll tell key stories from my identity journey — stories of the people, ideas, and lessons learned along the way. I’ll speak of technology and collaboration, usability and business models, solving problems people actually have, and building new ecosystems. Come with me on this journey of exploration, trials, triumphs, and humor as I recount touchstones of the human endeavor that is digital identity.

Kuppinger Cole has posted a video of my keynote on YouTube. I was pleased with how well it went. After the first few sentences, I was in the zone! I hope many of you find the messages in the talk useful.

My slides are also available in (PowerPoint) and PDF.

Special thanks go to the OpenID Foundation for supporting my trip to EIC this year and to designer Alistair Kincaid at MATTR for helping me transcend my usual black-bulleted-text-on-a-white-background presentation style!

EIC 2023 Keynote Photo

EIC 2023 Keynote Photo with Kim Cameron

EIC 2023 Keynote Photo for OAuth

Current Work and Future Trends in Selective Disclosure

EIC 2023 LogoThe session Current Work and Future Trends in Selective Disclosure at EIC 2023 covered a lot of foundational work happening in the space of Selective Disclosure right now. Selective Disclosure enables you to have a token with many claims (say, an ISO Mobile Drivers’ License (mDL)), and only release the claims necessary for the interaction — for instance, your birthdate but not your home address. Selective Disclosure enables Minimal Disclosure. This is sometimes realized using Zero Knowledge Proofs (ZKPs) but that’s not always necessary.

The agenda for the session was:

Our presentations are available in (PowerPoint) and PDF.

EIC 2023 Disclosure Issuer Holder Verifier Model

Initial Reanimiated JOSE Working Group Specifications Published

IETF logoFollowing a call for adoption by the restarted JSON Object Signing and Encryption (JOSE) Working Group, I’m pleased to report that the three initial working group specifications have been published. They are:

JSON Web Proof, with abstract:

This document defines a new container format similar in purpose and design to JSON Web Signature (JWS) called a JSON Web Proof (JWP). Unlike JWS, which integrity-protects only a single payload, JWP can integrity-protect multiple payloads in one message. It also specifies a new presentation form that supports selective disclosure of individual payloads, enables additional proof computation, and adds a protected header to prevent replay and support binding mechanisms.

JSON Proof Algorithms, with abstract:

The JSON Proof Algorithms (JPA) specification registers cryptographic algorithms and identifiers to be used with the JSON Web Proof (JWP) and JSON Web Key (JWK) specifications. It defines several IANA registries for these identifiers.

JSON Proof Token, with abstract:

JSON Proof Token (JPT) is a compact, URL-safe, privacy-preserving representation of claims to be transferred between three parties. The claims in a JPT are encoded as base64url-encoded JSON objects that are used as the payloads of a JSON Web Proof (JWP) structure, enabling them to be digitally signed and selectively disclosed. JPTs also support reusability and unlinkability when using Zero-Knowledge Proofs (ZKPs).

Thanks to Jeremie Miller and David Waite for helping us get there!

First Public Working Draft of Securing Verifiable Credentials using JSON Web Tokens

W3C logoThe First Public Working Draft (FPWD) of the Securing Verifiable Credentials using JSON Web Tokens (VC-JWT) specification has been published. The FPWD milestone is described in the W3C Process document. This draft is another step on the way to a Native JWT Representation for Verifiable Credentials.

Please review the First Public Working Draft of VC-JWT. Thanks especially to Orie Steele for making this happen!

Native JWT Representation for Verifiable Credentials

W3C logoFor the first time, there is now a native JSON Web Token (JWT) representation for Verifiable Credentials. This representation uses IANA-registered JWT claims whenever applicable. Among other improvements and simplifications, this means that we finally have a Verifiable Credentials representation that doesn’t require the use of JSON-LD.

The native JWT representation explicitly isn’t a mapping from the VC Data Model. This mapping in the VC 1.1 specification resulted in ambiguities about whether to duplicate VC Data Model claims in the VC-JWT representation (the “in addition to” option) or whether to delete them from the VC Data Model representation (the “instead of” option). These ambiguities harmed interoperability. Rather, the 2.0 VC-JWT representation is its own simpler native JWT data structure.

See the new native JWT VC representation in the Version 2 section of the “Securing Verifiable Credentials using JSON Web Tokens” specification. You can also compare it there to the Version 1.1 representation, which is a mapping from the VC Data Model with the “in addition to” and “instead of” choices.

This accomplishment is the product of the vision, passion, and perseverance of many advocates of simplifying Verifiable Credentials. Foremost among them is Orie Steele – my co-editor for the VC-JWT specification. I’ll also observe that the pull request creating this functionality had an unprecedented fifteen approvers – an indication of the broad support for this direction for Verifiable Credentials. I am proud to have played a role in making it happen.

JWK Thumbprint URI Draft Addressing IETF Last Call Comments

OAuth logoKristina Yasuda and I have published a new JWK Thumbprint URI draft that addresses the IETF Last Call comments received. Changes made were:

  • Clarified the requirement to use registered hash algorithm identifiers.
  • Acknowledged IETF Last Call reviewers.

The specification is available at:

Two new COSE- and JOSE-related Internet Drafts with Tobias Looker

IETF logoThis week, Tobias Looker and I submitted two individual Internet Drafts for consideration by the COSE working group.

The first is “Barreto-Lynn-Scott Elliptic Curve Key Representations for JOSE and COSE“, the abstract of which is:


This specification defines how to represent cryptographic keys for the pairing-friendly elliptic curves known as Barreto-Lynn-Scott (BLS), for use with the key representation formats of JSON Web Key (JWK) and COSE (COSE_Key).

These curves are used in Zero-Knowledge Proof (ZKP) representations for JOSE and COSE, where the ZKPs use the CFRG drafts “Pairing-Friendly Curves” and “BLS Signatures“.

The second is “CBOR Web Token (CWT) Claims in COSE Headers“, the abstract of which is:


This document describes how to include CBOR Web Token (CWT) claims in the header parameters of any COSE structure. This functionality helps to facilitate applications that wish to make use of CBOR Web Token (CWT) claims in encrypted COSE structures and/or COSE structures featuring detached signatures, while having some of those claims be available before decryption and/or without inspecting the detached payload.

JWTs define a mechanism for replicating claims as header parameter values, but CWTs have been missing the equivalent capability to date. The use case is the same as that which motivated Section 5.3 of JWT “Replicating Claims as Header Parameters” – encrypted CWTs for which you’d like to have unencrypted instances of particular claims to determine how to process the CWT prior to decrypting it.

We plan to discuss both with the COSE working group at IETF 113 in Vienna.

OAuth 2.0 JWT-Secured Authorization Request (JAR) is now RFC 9101

IETF logoThe OAuth 2.0 JWT-Secured Authorization Request (JAR) specification has been published as RFC 9101. Among other applications, this specification is used by the OpenID Financial-grade API (FAPI). This is another in the series of RFCs bringing OpenID Connect-defined functionality to OAuth 2.0. Previous such RFCs included “OAuth 2.0 Dynamic Client Registration Protocol” [RFC 7591] and “OAuth 2.0 Authorization Server Metadata” [RFC 8414].

The abstract of the RFC is:


The authorization request in OAuth 2.0 described in RFC 6749 utilizes query parameter serialization, which means that authorization request parameters are encoded in the URI of the request and sent through user agents such as web browsers. While it is easy to implement, it means that a) the communication through the user agents is not integrity protected and thus, the parameters can be tainted, b) the source of the communication is not authenticated, and c) the communication through the user agents can be monitored. Because of these weaknesses, several attacks to the protocol have now been put forward.


This document introduces the ability to send request parameters in a JSON Web Token (JWT) instead, which allows the request to be signed with JSON Web Signature (JWS) and encrypted with JSON Web Encryption (JWE) so that the integrity, source authentication, and confidentiality properties of the authorization request are attained. The request can be sent by value or by reference.

Thanks to Nat Sakimura and John Bradley for persisting in finishing this RFC!

OAuth 2.0 JWT Secured Authorization Request (JAR) sent back to the RFC Editor

OAuth logoAs described in my last post about OAuth JAR, after it was first sent to the RFC Editor, the IESG requested an additional round of IETF feedback. I’m happy to report that, having addressed this feedback, the spec has now been sent back to the RFC Editor.

As a reminder, this specification takes the JWT Request Object from Section 6 of OpenID Connect Core (Passing Request Parameters as JWTs) and makes this functionality available for pure OAuth 2.0 applications — and does so without introducing breaking changes. This is one of a series of specifications bringing functionality originally developed for OpenID Connect to the OAuth 2.0 ecosystem. Other such specifications included OAuth 2.0 Dynamic Client Registration Protocol [RFC 7591] and OAuth 2.0 Authorization Server Metadata [RFC 8414].

The specification is available at:

An HTML-formatted version is also available at:

OAuth 2.0 JWT Secured Authorization Request (JAR) updates addressing remaining review comments

OAuth logoAfter the OAuth 2.0 JWT Secured Authorization Request (JAR) specification was sent to the RFC Editor, the IESG requested an additional round of IETF feedback. We’ve published an updated draft addressing the remaining review comments, specifically, SecDir comments from Watson Ladd. The only normative change made since the 28 was to change the MIME Type from “oauth.authz.req+jwt” to “oauth-authz-req+jwt“, per advice from the designated experts.

As a reminder, this specification takes the JWT Request Object from Section 6 of OpenID Connect Core (Passing Request Parameters as JWTs) and makes this functionality available for pure OAuth 2.0 applications — and does so without introducing breaking changes. This is one of a series of specifications bringing functionality originally developed for OpenID Connect to the OAuth 2.0 ecosystem. Other such specifications included OAuth 2.0 Dynamic Client Registration Protocol [RFC 7591] and OAuth 2.0 Authorization Server Metadata [RFC 8414].

The specification is available at:

An HTML-formatted version is also available at:

OAuth 2.0 JWT Secured Authorization Request (JAR) sent to the RFC Editor

OAuth logoCongratulations to Nat Sakimura and John Bradley for progressing the OAuth 2.0 JWT Secured Authorization Request (JAR) specification from the working group through the IESG to the RFC Editor. This specification takes the JWT Request Object from Section 6 of OpenID Connect Core (Passing Request Parameters as JWTs) and makes this functionality available for pure OAuth 2.0 applications — and intentionally does so without introducing breaking changes.

This is one of a series of specifications bringing functionality originally developed for OpenID Connect to the OAuth 2.0 ecosystem. Other such specifications included OAuth 2.0 Dynamic Client Registration Protocol [RFC 7591] and OAuth 2.0 Authorization Server Metadata [RFC 8414].

The specification is available at:

An HTML-formatted version is also available at:

Again, congratulations to Nat and John and the OAuth Working Group for this achievement!

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