Archive for the 'Claims' Category

November 6, 2019
Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) sent to the RFC Editor

OAuth logoI’m pleased to report that the Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) specification is now technically stable and will shortly be an RFC – an Internet standard. Specifically, it has now progressed to the RFC Editor queue, meaning that the only remaining step before finalization is editorial due diligence. Thus, implementations can now utilize the draft specification with confidence that that breaking changes will not occur as it is finalized.

The abstract of the specification is:

This specification describes how to declare in a CBOR Web Token (CWT) (which is defined by RFC 8392) that the presenter of the CWT possesses a particular proof-of-possession key. Being able to prove possession of a key is also sometimes described as being the holder-of-key. This specification provides equivalent functionality to “Proof-of-Possession Key Semantics for JSON Web Tokens (JWTs)” (RFC 7800) but using Concise Binary Object Representation (CBOR) and CWTs rather than JavaScript Object Notation (JSON) and JSON Web Tokens (JWTs).

Thanks to the ACE working group for completing this important specification.

The specification is available at:

An HTML-formatted version is also available at:

October 22, 2019
JSON Web Token Best Current Practices sent to the RFC Editor

OAuth logoI’m pleased to report that the JSON Web Token (JWT) Best Current Practices (BCP) specification is now technically stable and will shortly be an RFC – an Internet standard. Specifically, it has now progressed to the RFC Editor queue, meaning that the only remaining step before finalization is editorial due diligence. Thus, implementations can now utilize the draft specification with confidence that that breaking changes will not occur as it is finalized.

The abstract of the specification is:

JSON Web Tokens, also known as JWTs, are URL-safe JSON-based security tokens that contain a set of claims that can be signed and/or encrypted. JWTs are being widely used and deployed as a simple security token format in numerous protocols and applications, both in the area of digital identity, and in other application areas. The goal of this Best Current Practices document is to provide actionable guidance leading to secure implementation and deployment of JWTs.

Thanks to the OAuth working group for completing this important specification.

The specification is available at:

An HTML-formatted version is also available at:

October 21, 2019
Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) spec addressing Gen-ART and SecDir reviews

IETF logoA new version of the Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) specification has been published addressing the Gen-ART and SecDir review comments. Thanks to Christer Holmberg and Yoav Nir, respectively, for these useful reviews.

The specification is available at:

An HTML-formatted version is also available at:

October 1, 2019
Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) spec addressing remaining Area Director comments

IETF logoA new version of the Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) specification has been published to address the remaining Area Director review comments by Benjamin Kaduk. Thanks to Ludwig Seitz for doing the bulk of the editing for this version.

The specification is available at:

An HTML-formatted version is also available at:

September 19, 2019
Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) spec addressing Area Director review comments

IETF logoThe Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) specification has been updated to address the Area Director review comments by Benjamin Kaduk. Thanks to Ludwig Seitz and Hannes Tschofenig for their work on resolving the issues raised.

The specification is available at:

An HTML-formatted version is also available at:

July 24, 2019
OAuth 2.0 Token Exchange specification sent to the RFC Editor

OAuth logoI’m very pleased to report that the OAuth 2.0 Token Exchange specification is now technically stable and will shortly be an RFC – an Internet standard. Specifically, it has now progressed to the RFC Editor queue, meaning that the only remaining step before finalization is editorial due diligence. Thus, implementations can now utilize the draft specification with confidence that that breaking changes will not occur as it is finalized.

The abstract of the specification is:

This specification defines a protocol for an HTTP- and JSON-based Security Token Service (STS) by defining how to request and obtain security tokens from OAuth 2.0 authorization servers, including security tokens employing impersonation and delegation.

Thanks to the OAuth working group for completing this important specification. And thanks to Brian Campbell for taking point in making the recent updates to get us here.

The specification is available at:

An HTML-formatted version is also available at:

February 21, 2019
Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) spec fixing nits

IETF logoThe Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) specification has been updated to address issues identified by Roman Danyliw while writing his shepherd review. Thanks to Samuel Erdtman for fixing an incorrect example.

The specification is available at:

An HTML-formatted version is also available at:

November 9, 2018
Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) spec adding Key ID considerations

IETF logoKey ID confirmation method considerations suggested by Jim Schaad have been added to the Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) specification. Per discussions in the working group meeting in Bangkok, it’s now time for the shepherd review.

The specification is available at:

An HTML-formatted version is also available at:

November 8, 2018
JWT BCP updates addressing Area Director review comments

OAuth logoThe JSON Web Token (JWT) Best Current Practices (BCP) specification has been updated to address the review comments from Security Area Director (AD) Eric Rescorla. Thanks to Eric for the review and to Yaron Sheffer for working on the responses with me.

Note that IETF publication has already been requested. The next step is for the shepherd review to be submitted and responded to.

The specification is available at:

An HTML-formatted version is also available at:

November 6, 2018
Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) spec addressing additional WGLC comments

IETF logoThe Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) specification has been updated to addresses a few additional Working Group Last Call (WGLC) comments. All of the (few) changes were about improving the clarity of the exposition. I believe that this completes addressing the WGLC comments.

Thanks to Roman Danyliw for helping to categorize the remaining comments that needed to be addressed.

The specification is available at:

An HTML-formatted version is also available at:

July 10, 2018
Security Event Token (SET) is now RFC 8417

IETF logoThe Security Event Token (SET) specification is now RFC 8417. The abstract describes the specification as:

This specification defines the Security Event Token (SET) data structure. A SET describes statements of fact from the perspective of an issuer about a subject. These statements of fact represent an event that occurred directly to or about a security subject, for example, a statement about the issuance or revocation of a token on behalf of a subject. This specification is intended to enable representing security- and identity-related events. A SET is a JSON Web Token (JWT), which can be optionally signed and/or encrypted. SETs can be distributed via protocols such as HTTP.

SETs are already in use to represent OpenID Connect Back-Channel Logout tokens and to represent Risk and Incident Sharing and Coordination (RISC) events. Thanks to my co-editors, members of the IETF ID Events mailing list, and members of the IETF Security Events working group for making this standard a reality!

June 29, 2018
Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) spec addressing WGLC comments

IETF logoA new draft of the Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs) specification has been published that addresses the Working Group Last Call (WGLC) comments received. Changes were:

Thanks to Samuel Erdtman and Hannes Tschofenig for contributing to the editing for this version and to Jim Schaad and Roman Danyliw for their review comments.

The specification is available at:

An HTML-formatted version is also available at:

June 28, 2018
OAuth 2.0 Authorization Server Metadata is now RFC 8414

OAuth logoThe OAuth 2.0 Authorization Server Metadata specification is now RFC 8414. The abstract describes the specification as:

This specification defines a metadata format that an OAuth 2.0 client can use to obtain the information needed to interact with an OAuth 2.0 authorization server, including its endpoint locations and authorization server capabilities.

The specification defines a JSON metadata representation for OAuth 2.0 authorization servers that is compatible with OpenID Connect Discovery 1.0. This specification is a true instance of standardizing existing practice. OAuth 2.0 deployments have been using the OpenID Connect metadata format to describe their endpoints and capabilities for years. This RFC makes this existing practice a standard.

Having a standard OAuth metadata format makes it easier for OAuth clients to configure connections to OAuth authorization servers. See https://www.iana.org/assignments/oauth-parameters/oauth-parameters.xhtml#authorization-server-metadata for the initial set of registered metadata values.

Thanks to all of you who helped make this standard a reality!

May 9, 2018
Security Event Token (SET) updates addressing IESG feedback

IETF logoWe’ve updated the Security Event Token (SET) specification to address feedback received from Internet Engineering Steering Group (IESG) members. We’ve actually published three versions in quick succession in preparation for tomorrow’s evaluation by the IESG.

Draft -11 incorporated feedback from Security Area Director Eric Rescorla and IANA Designated Expert Ned Freed. Changes were:

  • Clarified “iss” claim language about the SET issuer versus the security subject issuer.
  • Changed a “SHOULD” to a “MUST” in the “sub” claim description to be consistent with the Requirements for SET Profiles section.
  • Described the use of the “events” claim to prevent attackers from passing off other kinds of JWTs as SETs.
  • Stated that SETs are to be signed by an issuer that is trusted to do so for the use case.
  • Added quotes in the phrase ‘”token revoked” SET to be issued’ in the Timing Issues section.
  • Added section number references to the media type and media type suffix registrations.
  • Changed the encodings of the media type and media type suffix registrations to binary (since no line breaks are allowed).
  • Replaced a “TBD” in the media type registration with descriptive text.
  • Acknowledged Eric Rescorla and Ned Freed.

Draft -12 incorporated feedback from Adam Roach, Alexey Melnikov, and Alissa Cooper. Changes were:

  • Removed unused references to RFC 7009 and RFC 7517.
  • Corrected name of RFC 8055 in Section 4.3 to “Session Initiation Protocol (SIP) Via Header Field Parameter to Indicate Received Realm”.
  • Added normative references for base64url and UTF-8.
  • Section 5.1 – Changed SHOULD to MUST in “personally identifiable information MUST be encrypted using JWE [RFC7516] or …”.
  • Section 5.2 – Changed “MUST consider” to “must consider”.
  • Acknowledged Adam Roach, Alexey Melnikov, and Alissa Cooper.

Draft -13 incorporated feedback from Martin Vigoureaux. Changes were:

  • Changed a non-normative “MAY” to “may” in Section 1.1.
  • Acknowledged Martin Vigoureux and Mirja Kühlewind.

The specification is available at:

An HTML-formatted version is also available at:

May 9, 2018
JWT BCP updates addressing WGLC feedback

OAuth logoThe JSON Web Token (JWT) Best Current Practices (BCP) specification has been updated to address the Working Group Last Call (WGLC) feedback received. Thanks to Neil Madden for his numerous comments and to Carsten Bormann and Brian Campbell for their reviews.

Assuming the chairs concur, the next step should be to request publication.

The specification is available at:

An HTML-formatted version is also available at:

May 8, 2018
“CBOR Web Token (CWT)” is now RFC 8392

IETF logoThe “CBOR Web Token (CWT)” specification is now RFC 8392 – an IETF standard. The abstract for the specification is:

CBOR Web Token (CWT) is a compact means of representing claims to be transferred between two parties. The claims in a CWT are encoded in the Concise Binary Object Representation (CBOR) and CBOR Object Signing and Encryption (COSE) is used for added application-layer security protection. A claim is a piece of information asserted about a subject and is represented as a name/value pair consisting of a claim name and a claim value. CWT is derived from JSON Web Token (JWT) but uses CBOR rather than JSON.

Special thanks to Erik Wahlström for starting this work and to Samuel Erdtman for doing most of the heavy lifting involved in creating correct and useful CBOR and COSE examples.

Next up – finishing “Proof-of-Possession Key Semantics for CBOR Web Tokens (CWTs)”, which provides the CWT equivalent of “Proof-of-Possession Key Semantics for JSON Web Tokens (JWTs)” [RFC 7800].

May 1, 2018
Security Event Token (SET) spec addressing additional SecDir review comments

IETF logoAn updated Security Event Token (SET) specification has published to address recent review comments received. Changes were:

  • Incorporated wording improvements resulting from Russ Housley’s additional SecDir comments.
  • Registered +jwt structured syntax suffix.

The specification is available at:

An HTML-formatted version is also available at:

April 24, 2018
Late-breaking changes to OAuth Token Exchange syntax

OAuth logoThe syntax of two JWT claims registered by the OAuth Token Exchange specification has been changed as a result of developer feedback. Developers pointed out that the OAuth Token Introspection specification [RFC 7662] uses a “scope” string to represent scope values, whereas Token Exchange was defining an array-valued “scp” claim to represent scope values. The former also uses a “client_id” element to represent OAuth Client ID values, whereas the latter was using a “cid” claim for the same purpose.

After consulting with the working group, the OAuth Token Exchange claim names have been changed to “scope” and “client_id”. Thanks to Torsten Lodderstedt for pointing out the inconsistencies and to Brian Campbell for seeking consensus and making the updates.

The specification is available at:

An HTML-formatted version is also available at:

April 17, 2018
Security Event Token (SET) spec addressing Area Director review comments

IETF logoThe Security Event Token (SET) specification has been updated to address Area Director review comments from Benjamin Kaduk. Thanks for the thorough and useful review, as always, Ben.

The specification is available at:

An HTML-formatted version is also available at:

April 4, 2018
Security Event Token (SET) spec addressing SecDir review comments

IETF logoA new draft of the Security Event Token (SET) specification has published that addresses comments from Russ Housley, who reviewed the spec for the IETF Security Directorate (SecDir). Changes were:

  • Incorporated wording improvements resulting from Russ Housley’s SecDir comments.
  • Acknowledged individuals who made significant contributions.

The specification is available at:

An HTML-formatted version is also available at:

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