Mike Jones: self-issued

Musings on Digital Identity

Category: Cryptography Page 1 of 11

Essential Moments in the OAuth and OpenID Timeline

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On May 20, 2025

In Claims, Cryptography, Interoperability, JSON, OAuth, OpenID, Security, Specifications

OpenID logoOAuth logoDuende Software just posted an insightful piece titled Essential Moments in the OAuth and OpenID Connect Timeline. It’s a trip down memory lane, recounting significant developments in the identity and security standards repertoire that we now take for granted.

It reminds us that all of this has come about in the last 15 years. These standards didn’t happen by accident. They were all created to meet specific needs that we understood at the time. Fortunately, they’ve also largely stood the test of time. I’m proud to have been involved in creating many of them – of course, always in close collaboration with others.

W3C Verifiable Credentials 2.0 Specifications are Now Standards

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On May 15, 2025

In CBOR, Claims, Cryptography, JSON, Specifications, W3C

W3C logoAs announced by the W3C, the Verifiable Credentials 2.0 family of specifications is now a W3C Recommendation. The new W3C Recommendations that I was an editor for are:

I joined the VC 2.0 journey in 2022 with the goal of there being a simple, secure, standards-based way to sign W3C Verifiable Credentials. The VC-JOSE-COSE specification accomplishes that – defining how to secure VC Data Model payloads with JOSE, SD-JWT, or COSE signatures. As I wrote when the Proposed Recommendations were published, while I’m admittedly not a fan of JSON-LD, to the extent that Verifiable Credentials using the JSON-LD-based VC Data Model are in use, I was committed to there being a solid VC-JOSE-COSE specification so there is a simple, secure, standards-based way to secure these credentials. That goal is now accomplished.

Particular thanks go to my co-editors of VC-JOSE-COSE Gabe Cohen and Mike Prorock, former editor Orie Steele, and working group chair Brent Zundel for the significant work they all both put in throughout the journey. And of course, Manu Sporny and Ivan Herman were always diligent about moving things along.

One of my personal mottos is “Finishing things matters”. This is now finished. As the song says, “What a long, strange trip it’s been”!

Fully-Specified Algorithms are now the Law of the Land

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On May 13, 2025

In CBOR, Cryptography, IETF, JSON, Specifications

IETF logoI’m thrilled to be able to report that, from now on, only fully-specified algorithms will be registered for JOSE and COSE. Furthermore, fully-specified signature algorithms are now registered to replace the previously registered polymorphic algorithms, which are now deprecated. For example, you can now use Ed25519 and Ed448 instead of the ambiguous EdDSA.

The new IANA JOSE registrations and IANA COSE registrations are now in place, as are the deprecations of the polymorphic signing algorithms. And perhaps most significantly for the long term, the instructions to the designated experts for both registries have been updated so that only fully-specified algorithms will be registered going forward.

Lots of people deserve credit for this significant improvement to both ecosystems. Filip Skokan was the canary in the coal mine, alerting the OpenID Connect working group to the problems with trying to sign with Ed25519 and Ed448 when there were no algorithm identifiers that could be used to specify their use. Similarly, John Bradley alerted the WebAuthn working group to the same problems for WebAuthn and FIDO2, devising the clever and awful workaround that, when used by those specs, EdDSA is to be interpreted as meaning Ed25519. John also supported this work as a JOSE working group chair. Roman Danyliw supported including the ability to specify the use of fully-specified algorithms in the JOSE charter as the Security Area Director then responsible for JOSE. Karen O’Donoghue created the shepherd write-up as JOSE co-chair. Deb Cooley thoroughly reviewed and facilitated advancement of the specification as the Security Area Director currently responsible for JOSE. And of course, Orie Steele, the co-inventor of the fully-specified algorithms idea, and my co-author since our audacious proposal to fix the polymorphic algorithms problem at IETF 117 in July 2023 deserves huge credit for making the proposal a reality!

The specification is now in the RFC Editor Queue. I can’t wait until it pops out the other side as an RFC!

The specification is available at:

Thanks to all who helped make fully-specified algorithms the law of the land!

Fully-Specified Algorithms Specification Addressing IESG Feedback

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On May 6, 2025

In CBOR, Cryptography, IETF, JSON, Specifications

IETF logoOrie Steele and I have updated the “Fully-Specified Algorithms for JOSE and COSE” specification to address feedback received through directorate reviews and from Internet Engineering Steering Group (IESG) members. This prepares us for consideration of the specification by the IESG during its “telechat” on Thursday. This is an important milestone towards progressing the specification to become an RFC.

Changes made since I last wrote about the spec, as summarized in the history entries, are:

-11

  • Stated in the abstract that the specification deprecates some polymorphic algorithm identifiers, as suggested by Éric Vyncke.

-10

  • Provided a complete list of the Recommended column terms for COSE registrations, as suggested by Mohamed Boucadair.
  • Applied suggestions to improve the exposition received during IESG review.

-09

  • Addressed comments from secdir review by Kathleen Moriarty.

-08

  • Updated requested Brainpool algorithm numbers to match those chosen by Sean Turner.
  • Incorporated wording suggestions by Vijay Gurbani.

The specification is available at:

Hybrid Public Key Encryption (HPKE) for JOSE incorporating feedback from IETF 122

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On April 25, 2025

In Cryptography, IETF, JSON, Specifications

IETF logoThe “Use of Hybrid Public-Key Encryption (HPKE) with JSON Object Signing and Encryption (JOSE)” specification has updated to incorporate feedback from IETF 122 in Bangkok.

Per the History entries, the changes were:

  • Use "enc":"int" for integrated encryption.
  • Described the reasons for excluding authenticated HPKE.
  • Stated that mutually known private information MAY be used as the HPKE info value.

At this point, the authors have closed all the issues and PRs that we believe there’s consensus to address. I would normally suggest that we’re ready for working group last call at this point, but I’d like us to take the extra step to verify that the spec is aligned with the COSE HPKE spec first. Both as an author of the JOSE HPKE spec and as a COSE chair interested in the COSE HPKE spec, I’d request that members of both working groups review the specs together and send their feedback.

Third Version of FIDO2 Client to Authenticator Protocol (CTAP 2.2) Now a Standard

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On March 18, 2025

In Cryptography, FIDO, Phishing Resistance, Privacy, Specifications, W3C

FIDO logoThe FIDO Alliance has completed the CTAP 2.2 Specification. The closely-related third version of the W3C Web Authentication (WebAuthn) specification is also nearing final status; this WebAuthn Level 3 working draft is currently going through the review steps to become a W3C Recommendation.

So what’s new in the third versions?

Changes between CTAP 2.1 and CTAP 2.2 are:

Changes between WebAuthn Level 2 and the WebAuthn Level 3 working draft are described in the document’s Revision History.

Completing these V3 specifications represents important progress in our quest to free us from the password!

Fully-Specified Algorithms Specification Addressing Area Director Feedback

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On March 7, 2025

In CBOR, Cryptography, IETF, JSON, Specifications

IETF logoOrie Steele and I want to thank Deb Cooley for her Area Director review of the “Fully-Specified Algorithms for JOSE and COSE” specification. Addressing it simplified the exposition, while preserving the essence of what the draft accomplishes.

Specifically, the resulting draft significantly simplified the fully-specified encryption description and removed the appendix on polymorphic ECDH algorithms. We also stated that HSS-LMS is not fully specified, as suggested by John Preuß Mattsson.

The draft has now completed IETF last call, with the two resulting reviews stating that the draft is ready for publication.

The specification is available at:

COSE Algorithms for Two-Party Signing

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On March 3, 2025

In CBOR, Cryptography, FIDO, IETF, Specifications, W3C

IETF logoEmil Lundberg and I have published the COSE Algorithms for Two-Party Signing specification. Its abstract is:

This specification defines COSE algorithm identifiers used when the signing operation is performed cooperatively between two parties. When performing two-party signing, the first party typically hashes the data to be signed and the second party signs the hashed data computed by the first party. This can be useful when communication with the party holding the signing private key occurs over a limited-bandwidth channel, such as NFC or Bluetooth Low Energy (BLE), in which it is infeasible to send the complete set of data to be signed. The resulting signatures are identical in structure to those computed by a single party, and can be verified using the same verification procedure without additional steps to preprocess the signed data.

A motivating use case for this is for WebAuthn/FIDO2 Authenticators to use when signing application data, as described in the proposed WebAuthn signing extension. Parts of this spec’s content were previously in the Asynchronous Remote Key Generation (ARKG) algorithm spec, which we’ve also been updated.

I plan to talk about the spec during IETF 122 in Bangkok. I hope to see many of you there!

The specification is available at:

This work was supported by the SIROS Foundation.

Proposed Candidate Recommendation for Controlled Identifiers

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On February 4, 2025

In Cryptography, JSON, Specifications, W3C

W3C logoThe W3C Verifiable Credentials Working Group has published a Snapshot Candidate Recommendation of the Controlled Identifiers specification. This follows the five Candidate Recommendation Snapshots published by the working group in December 2024. Two of these specifications, including Securing Verifiable Credentials using JOSE and COSE, depend upon the Controlled Identifiers spec. The planned update to the W3C DID specification also plans to take a dependency upon it.

A W3C Candidate Recommendation Snapshot is intended to become a W3C Candidate Recommendation after required review and approval steps.

Thanks to my co-editor Manu Sporny and working group chair Brent Zundel for their work enabling us to reach this point.

Proposed Second Candidate Recommendation for Securing Verifiable Credentials using JOSE and COSE

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On January 2, 2025

In CBOR, Claims, Cryptography, JSON, Specifications, W3C

W3C logoThe W3C Verifiable Credentials Working Group published the Snapshot Second Candidate Recommendation of the Securing Verifiable Credentials using JOSE and COSE specification just before the holidays. This was one of five Candidate Recommendation Snapshots published by the working group at the same time, including for the Verifiable Credentials Data Model 2.0, which I’m also an editor of. A W3C Candidate Recommendation Snapshot is intended to become a W3C Candidate Recommendation after required review and approval steps.

As I wrote about the First Candidate Recommendation, VC-JOSE-COSE secures VC Data Model payloads with JOSE, SD-JWT, or COSE signatures. And while I’m admittedly not a fan of JSON-LD, to the extent that Verifiable Credentials using the JSON-LD-based VC Data Model are in use, I’m committed to there being a solid VC-JOSE-COSE specification so there is a simple, secure, standards-based way to sign these credentials.

One significant change since the First Candidate Recommendation was splitting the Controller Document text out into its own specification called Controlled Identifier Document 1.0. Publishing a Candidate Recommendation Snapshot for it is planned for next week. Part of why it became its own specification is so that it can be referenced by the planned update to the W3C DID specification.

Thanks to my co-editor Gabe Cohen and working group chair Brent Zundel for the significant work they both put in to help us reach this point!

Fully-Specified Algorithms Specification Addressing Feedback from IETF 120

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On August 2, 2024

In CBOR, Cryptography, IETF, JSON, Specifications

IETF logoOrie Steele and I have updated the “Fully-Specified Algorithms for JOSE and COSE” specification to incorporate feedback from IETF 120 in Vancouver. Specifically, the registrations for fully-specified Elliptic Curve Diffie-Hellman (ECDH) algorithms in draft 03 were removed, along with the previously proposed fully-specified ECDH algorithm identifiers, while continuing to describe how to create fully-specified ECDH algorithms in the future, if needed.

The specification is available at:

Fully-Specified Algorithms Specification Addressing Working Group Last Call Comments

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On July 11, 2024

In CBOR, Cryptography, IETF, JSON, Specifications

IETF logoOrie Steele and I have updated the “Fully-Specified Algorithms for JOSE and COSE” specification to incorporate working group last call (WGLC) feedback. Thanks to all who took the time to comment on the draft. Your feedback was exceptionally actionable and helped to substantially improve the specification. Responses to each WGLC comment thread were sent on the IETF JOSE working group mailing list.

The updated draft attempts to discuss the full range of the problems created by polymorphic algorithm identifiers. Guided by working group feedback, it strikes an engineering balance between which of these problems to fix immediately in the specification and which to describe how future specifications can fix later as the need arises.

I look forward to discussing next steps for the specification at IETF 120 in Vancouver.

The specification is available at:

Standards are About Making Choices

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On June 9, 2024

In CBOR, Claims, Cryptography, Events, FIDO, IETF, Interoperability, JSON, OAuth, OpenID, Phishing Resistance, Specifications, W3C

EIC 2024 LogoI was honored to give the keynote presentation Standards are About Making Choices at the 2024 European Identity and Cloud Conference (EIC) (PowerPoint) (PDF). The abstract was:

When building machines, we take for granted being able to use nuts, bolts, wires, light bulbs, and countless other parts made to industry standards. Standards contain choices about dimensions of screw threads, nut sizes, etc., enabling a marketplace of interoperable parts from multiple suppliers. Without these choices, every part would be custom manufactured. The same is true of the identity and security standards we use to build identity systems.

However, the identity and security standards at our disposal differ wildly in the degree to which they do and don’t make choices. Some consistently define ONE way to do things, resulting in everyone doing it that way (interoperability!). Others leave critical choices unmade, passing the buck to implementers and applications (your mileage may vary).

In this talk, I’ll name names and take prisoners, critiquing existing and emerging standards through the lens of the choices they made and failed to make. Hold on to your hats as we examine the pros and cons of the choices made by OAuth, SAML, X.509, OpenID Connect, Verifiable Credentials, DIDs, WebCrypto, JOSE, COSE, and many others through this lens!

I believe you’ll agree with me that making choices matters.

The conference keynote description includes a recording of the presentation.

Thanks to MATTR for providing a designer to work with me on the presentation, enabling the visual design to transcend my usual black-text-on-white-background design style!

Using Standards: Some Assembly Required

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On May 30, 2024

In CBOR, Claims, Cryptography, Events, FIDO, IETF, Interoperability, JSON, OAuth, OpenID, Phishing Resistance, Specifications, W3C

Identiverse LogoI gave the following presentation in the session Using Standards: Some Assembly Required at the 2024 Identiverse conference (PowerPoint) (PDF). The abstract was:

  • Standards are about making choices. When building machines, we take for granted being able to use nuts, bolts, wires, light bulbs, and countless other parts made to industry standards. Standards contain choices about dimensions of screw threads, nut sizes, etc., enabling a marketplace of interoperable parts from multiple suppliers. Without these choices, every part would be custom-manufactured. The same is true of the identity and security standards we use to build the Identity Engine. However, the identity and security standards at our disposal differ wildly in the degree to which they do and don’t make choices. Some consistently define ONE way to do things, resulting in everyone doing it that way (interoperability!). Others leave critical choices unmade, passing the buck to implementers and applications (your mileage may vary). In this talk, I’ll name names and take prisoners, critiquing existing and emerging standards through the lens of the choices they made and failed to make. Hold on to your hats as we examine the pros and cons of the choices made by OAuth, SAML, X.509, OpenID Connect, Verifiable Credentials, DIDs, WebCrypto, JOSE, COSE, and many others through this lens! I believe you’ll agree with me that making choices matters.

The audience was highly engaged by the process of giving existing and emerging standards letter grades based on the choices they made (or failed to make)!

Securing Verifiable Credentials using JOSE and COSE is now a W3C Candidate Recommendation

By

On April 28, 2024

In CBOR, Claims, Cryptography, JSON, Specifications, W3C

W3C logoThe Securing Verifiable Credentials using JOSE and COSE specification (a.k.a. VC-JOSE-COSE) has reached W3C Candidate Recommendation status. The Candidate Recommendation milestone is described in the W3C Process document. Please review the Candidate Recommendation of VC-JOSE-COSE. Thanks especially to Gabe Cohen, Orie Steele, and Brent Zundel for doing the hard work of getting us to this point!

Since I last wrote about this work, the W3C Verifiable Credentials Data Model (VCDM), which is also at Candidate Recommendation stage, has been narrowed to only use JSON-LD to represent credentials. VC-JOSE-COSE secures VCDM payloads with JOSE, SD-JWT, or COSE signatures. While I’m admittedly not a fan of JSON-LD, to the extent that Verifiable Credentials using the VCDM are in use, I’m committed to finishing a solid VC-JOSE-COSE specification so there is a simple, secure, standards-based way to sign these credentials.

Of course, there are lots of Verifiable Credential formats to choose from, and more on the way. Choices already existing include ISO mDoc, IETF SD-JWT, IETF JSON Web Proof (JWP), and W3C VCDM. The IETF is also planning to create a CBOR-based selective disclosure representation in the newly formed SPICE working group. It will be interesting to see how these all shake out in the marketplace!

Fully-Specified Algorithms Presentation at 2024 OAuth Security Workshop

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On April 12, 2024

In Cryptography, Events, IETF, Specifications

OAuth Security WorkshopI gave a presentation on Fully-Specified Algorithms for JOSE and COSE at the 2024 OAuth Security Workshop in Rome. The slides used to update participants on the progress of the work are available as PowerPoint and PDF.

Thanks to the organizers for another great OAuth Security Workshop! And special thanks to the colleagues from Fondazione Bruno Kessler who did a great job with local arrangements in Rome!

Eight Specifications Published in Preparation for IETF 119

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On March 20, 2024

In CBOR, Claims, Cryptography, Events, IETF, JSON, Specifications

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!

Fully-Specified Algorithms adopted by JOSE working group

By

On January 31, 2024

In CBOR, Cryptography, IETF, JSON, Specifications

IETF logoThe “Fully-Specified Algorithms for JOSE and COSE” specification has been adopted by the JOSE working group. See my original post about the spec for why fully-specified algorithms matter. Thanks to all who supported adoption and also thanks to those who provided useful detailed feedback that we can address in future working group drafts.

The specification is available at:

Hybrid Public Key Encryption (HPKE) for JOSE

By

On October 31, 2023

In Cryptography, IETF, JSON, Specifications

IETF logoThe new “Use of Hybrid Public-Key Encryption (HPKE) with Javascript Object Signing and Encryption (JOSE)” specification has been published. Its abstract is:

This specification defines Hybrid public-key encryption (HPKE) for use with Javascript Object Signing and Encryption (JOSE). HPKE offers a variant of public-key encryption of arbitrary-sized plaintexts for a recipient public key.

HPKE works for any combination of an asymmetric key encapsulation mechanism (KEM), key derivation function (KDF), and authenticated encryption with additional data (AEAD) function. Authentication for HPKE in JOSE is provided by JOSE-native security mechanisms or by one of the authenticated variants of HPKE.

This document defines the use of the HPKE with JOSE.

Hybrid Public Key Encryption (HPKE) is defined by RFC 9180. There’s a whole new generation of specifications using it for encryption. The Messaging Layer Security (MLS) Protocol [RFC 9420] uses it. TLS Encrypted Client Hello uses it. Use of Hybrid Public-Key Encryption (HPKE) with CBOR Object Signing and Encryption (COSE) brings it to COSE. And this specification brings it to JOSE.

One of our goals for the JOSE HPKE specification is to keep it closely aligned with the COSE HPKE specification. That should be facilitated by having multiple authors in common, with Hannes Tschofenig and Orie Steele being authors of both, and me being a COSE co-chair.

Aritra Banerjee will be presenting the draft to the JOSE working group at IETF 118 in Prague. I’m hoping to see many of you there!

The specification is available at:

JSON Web Proofs specifications updated in preparation for IETF 118

By

On October 22, 2023

In Claims, Cryptography, IETF, JSON, Privacy, Specifications

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.

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