Tobias 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:
David 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.
The W3C WebAuthn and FIDO2 working groups have been actively creating third versions of the W3C Web Authentication (WebAuthn) and FIDO2 Client to Authenticator Protocol (CTAP) specifications. While remaining compatible with the original and second standards, these third versions add features that have been motivated by experience with deployments of the previous versions. Additions include Cross-Origin Authentication within an iFrame, Credential Backup State, the isPasskeyPlatformAuthenticatorAvailable method, Conditional Mediation, Device-Bound Public Keys (since renamed Supplemental Public Keys), requesting Attestations during authenticatorGetAssertion, the Pseudo-Random Function (PRF) extension, the Hybrid Transport, and Third-Party Payment Authentication.
I often tell people that I use my blog as my external memory. I thought I’d post references to these drafts to help me and others find them. They are:
Thanks to John Bradley for helping me compile the list of deltas!
Following 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!
I’m thrilled that the IETF has restarted the JSON Object Signing and Encryption (JOSE) Working Group. It’s chartered to work on JSON- and CBOR-based representations for Zero-Knowledge Proofs (ZKPs), selective disclosure enabling minimal disclosure, and non-correlatable presentation. The representations are planned to use the three-party model of Issuer, Holder, and Verifier utilized by Verifiable Credentials.
See the newly approved JOSE charter at https://datatracker.ietf.org/doc/charter-ietf-jose/03/. The working group will be chaired by Karen O’Donoghue, John Bradley, and John Mattsson, with the assigned area director being Roman Danyliw.
I believe this is a great outcome because the JOSE working group participants already have expertise creating simple, widely-adopted JSON-based cryptographic formats, such as JSON Web Signature (JWS), JSON Web Encryption (JWE), and JSON Web Key (JWK). The new formats will be peers to JWS, JWE, and COSE, reusing elements that make sense, while enabling use of new cryptographic algorithms whose inputs and outputs are not representable in the existing JOSE and COSE formats.
If you’re interested in the work, please join the JOSE mailing list at https://www.ietf.org/mailman/listinfo/jose if you’re not already a member. Also, plan to participate in IETF 116 Yokohama, where we should be able to have the first meeting of the reconstituted working group. I hope to see you there!
As background, the first step in the JOSE rechartering was the JSON Web Proofs (JWP) BoF at IETF 114 in Philadelphia sponsored by Security Area Director Roman Danyliw and chaired by Karen O’Donoghue and John Bradley, during which Jeremie Miller, Kristina Yasuda, Tobias Looker, and I presented. That was follwed by a Virtual Interim JWP BoF in October, 2022, review on the ietf-announce mailing list, and multiple IESG discussions.
All of which brings us back to the (now recurring!) question: “What Would JOSE Do?” Join us and be part of answering it!
This week at IETF 114 in Philadelphia, we held a Birds-of-a-Feather (BoF) session on JSON Web Proofs (JWPs). JSON Web Proofs are a JSON-based representation of cryptographic inputs and outputs that enable use of Zero-Knowledge Proofs (ZKPs), selective disclosure for minimal disclosure, and non-correlatable presentation. JWPs use the three-party model of Issuer, Holder, and Verifier utilized by Verifiable Credentials.
The BoF asked to reinstate the IETF JSON Object Signing and Encryption (JOSE) working group. We asked for this because the JOSE working group participants already have expertise creating simple, widely-adopted JSON-based cryptographic formats, such as JSON Web Signature (JWS), JSON Web Encryption (JWE), and JSON Web Key (JWK). The JWP format would be a peer to JWS and JWE, reusing elements that make sense, while enabling use of new cryptographic algorithms whose inputs and outputs are not representable in the existing JOSE formats.
Presentations given at the BoF were:
You can view the BoF minutes at https://notes.ietf.org/notes-ietf-114-jwp. A useful discussion ensued after the presentations. Unfortunately, we didn’t have time to finish the BoF in the one-hour slot. The BoF questions unanswered in the time allotted would have been along the lines of “Is the work appropriate for the IETF?”, “Is there interest in the work?”, and “Do we want to adopt the proposed charter?”. Discussion of those topics is now happening on the jose@ietf.org mailing list. Join it at https://www.ietf.org/mailman/listinfo/jose to participate. Roman Danyliw, the Security Area Director who sponsored the BoF, had suggested that we hold a virtual interim BoF to complete the BoF process before IETF 115 in London. Hope to see you there!
The BoF Presenters:
The BoF Participants, including the chairs:
The FIDO Alliance has completed the CTAP 2.1 Specification. This follows the publication of the closely-related second version of the W3C Web Authentication (WebAuthn) specification.
Today’s FIDO Alliance announcement describes the enhancements in the second version as follows:
Enhancements to FIDO standards to accelerate passwordless in the enterprise
The FIDO Alliance has announced enhancements to its FIDO2 specifications, which include several new features that will be helpful for passwordless enterprise deployments and other complex security applications. Both FIDO2 specifications were recently updated by their governing bodies — with the World Wide Web Consortium (W3C) approving WebAuthn Level 2 and FIDO doing the same for CTAP 2.1.
Key to these enhancements is enterprise attestation, which provides enterprise IT with improved management of FIDO authenticators used by employees. Enterprise attestation enables better binding of an authenticator to an account, assists with usage tracking and other management functions including credential and pin management, and biometric enrollment required in the enterprise.
Other updates include support for cross-origin iFrames and Apple attestation, as well as improvements to resident credentials. More details on these and other FIDO specification enhancements are available here.
The World Wide Web Consortium (W3C) has published this Recommendation for the Web Authentication (WebAuthn) Level 2 specification, meaning that it now a completed standard. While remaining compatible with the original standard, this second version adds additional features, among them for user verification enhancements, manageability, enterprise features, and an Apple attestation format. The companion second FIDO2 Client to Authenticator Protocol (CTAP) specification is also approaching becoming a completed standard.
See the W3C announcement of this achievement. Also, see Tim Cappalli‘s summary of the changes in the second versions of WebAuthn and FIDO2.
The FIDO Alliance has published this Public Review Draft for the FIDO2 Client to Authenticator Protocol (CTAP) specification, bringing the second version of FIDO2 one step closer to becoming a completed standard. While remaining compatible with the original standard, this second version adds additional features, among them for user verification enhancements, manageability, enterprise features, and an Apple attestation format.
This parallels the similar progress of the closely related second version of the W3C Web Authentication (WebAuthn) specification, which recently achieved Proposed Recommendation (PR) status.
The World Wide Web Consortium (W3C) has published this Proposed Recommendation (PR) for the Web Authentication (WebAuthn) Level 2 specification, bringing the second version of WebAuthn one step closer to becoming a completed standard. While remaining compatible with the original standard, this second version adds additional features, among them for user verification enhancements, manageability, enterprise features, and an Apple attestation format.
The W3C WebAuthn and FIDO2 working groups have been busy this year preparing to finish second versions of the W3C Web Authentication (WebAuthn) and FIDO2 Client to Authenticator Protocol (CTAP) specifications. While remaining compatible with the original standards, these second versions add additional features, among them for user verification enhancements, manageability, enterprise features, and an Apple attestation format. Near-final review drafts of both have been published:
Expect these to become approved standards in early 2021. Happy New Year!
I’m thrilled to report that the FIDO2 Client to Authenticator Protocol (CTAP) is now a published FIDO Alliance standard! Together with the now-standard Web Authentication (WebAuthn) specification, this completes standardization of the APIs and protocols needed to enable password-less logins on the Web, on PCs, and on and mobile devices. This is a huge step forward for online security, privacy, and convenience!
The FIDO2 CTAP standard is available in HTML and PDF versions at these locations:
I’m thrilled to report that the Web Authentication (WebAuthn) specification is now a W3C standard! See the W3C press release describing this major advance in Web security and convenience, which enables logging in without passwords. Alex Simons, Microsoft Vice President of Identity Program Management is quoted in the release, saying:
“Our work with W3C and FIDO Alliance, and contributions to FIDO2 standards have been a critical piece of Microsoft’s commitment to a world without passwords, which started in 2015. Today, Windows 10 with Microsoft Edge fully supports the WebAuthn standard and millions of users can log in to their Microsoft account without using a password.”
The release also describes commitments to the standard by Google, Mozilla, and Apple, among others. Thanks to all who worked on the standard and who built implementations as we developed the standard — ensuring that that the standard can be used for a broad set of use cases, including password-less sign-in with platform authenticators, mobile devices, and security keys.
The World Wide Web Consortium (W3C) has published a Proposed Recommendation (PR) for the Web Authentication (WebAuthn) specification, bringing WebAuthn one step closer to becoming a completed standard. The Proposed Recommendation is at https://www.w3.org/TR/2019/PR-webauthn-20190117/.
The PR contains only clarifications and editorial improvements to the second Candidate Recommendation (CR), with no substantial changes. The next step will be to publish a Recommendation – a W3C standard – based on the Proposed Recommendation.
W3C has published a second W3C Candidate Recommendation (CR) for the Web Authentication (WebAuthn) specification. The second Candidate Recommendation is at https://www.w3.org/TR/2018/CR-webauthn-20180807/.
This draft contains a few refinements since the first candidate recommendation but no substantial changes. The new CR was needed to fulfill the W3C’s IPR protection requirements. The few changes were based, in part, upon things learned during multiple interop events for WebAuthn implementations. The working group plans to base coming the Proposed Recommendation on this draft.
I’m pleased to report that a public Implementation Draft of the FIDO2 Client to Authenticator Protocol (CTAP) specification has been published. This specification enables FIDO2 clients, such as browsers implementing the W3C Web Authentication (WebAuthn) specification, to perform authentication using pairwise public/private key pairs securely held by authenticators speaking the CTAP protocol (rather than passwords). Use of three transports for communicating with authenticators is specified in the CTAP specification: USB Human Interface Device (USB HID), Near Field Communication (NFC), and Bluetooth Smart/Bluetooth Low Energy Technology (BLE).
This specification was developed in parallel with WebAuthn, including having a number of common authors. This CTAP version is aligned with the WebAuthn Candidate Recommendation (CR) version.
The CTAP Implementation Draft is available at:
Congratulations to the members of the FIDO2 working group for reaching this important milestone. This is a major step in our journey to deprecate the password!
The W3C Web Authentication (WebAuthn) specification is now a W3C Candidate Recommendation (CR). See the specification at https://www.w3.org/TR/2018/CR-webauthn-20180320/ and my blog post announcing this result for the WebAuthn working group at https://www.w3.org/blog/webauthn/2018/03/20/candidate-recommendation/.
This milestone represents a huge step towards enabling logins to occur using privacy-preserving public/private key pairs securely held by authenticators, rather than passwords. Its contents have been informed by what we learned during several rounds of interop testing by multiple browser and authenticator vendors. The Web Authentication spec has also progressed in parallel with and been kept in sync with the FIDO2 Client To Authenticator Protocol (CTAP) specification, so that they work well together.
This morning at the RSA conference, Scott Charney announced that Microsoft has licensed the U-Prove technology under the Open Specification Promise and released sample implementations in C# and Java under the BSD license. Implementers will be interested in two specifications: the “U-Prove Cryptographic Specification V1.0”, which documents U-Prove’s cryptographic operations, and “U-Prove Technology Integration into the Identity Metasystem V1.0”, which documents how to use U-Prove tokens with WS-Trust. These specifications are intended to enable interoperable implementations.
The U-Prove technologies enable two key properties: minimal disclosure and unlinkability. For more about U-Prove and today’s Community Technology Preview (CTP) release, see the Microsoft U-Prove site, the post announcing the release, and Vittorio’s post (with links to videos).
The Internet Safety Technical Task Force has released its report on online child safety: Enhancing Child Safety and Online Technologies: Final Report of the Internet Safety Technical Task Force to the Multi-State Working Group on Social Networking of State Attorneys General of the United States. During its year-long effort, the task force surveyed existing research and evaluated technologies that are relevant to child safety online.
One thing noticeably absent from the report, given the number of different technologies presented to and discussed by the task force, is references to any of them. In the end, the task force took the position that while technologies can help, that none is a silver bullet, and none are a substitute for parents and other adults who are active in children’s lives. I have to agree with them.
The Technical Advisory Board appointed by the task force evaluated possible technological approaches to making children safer online. A number of its members were individuals active in the identity and security communities, including Ben Adida of Harvard, Todd Inskeep of Bank of America, RL “Bob” Morgan of the University of Washington, and Danny Weitzner of MIT. The Technology Advisory Board Report summary included:
In sum, the TAB review of the submitted technologies leaves us in a state of cautious optimism, with many submissions showing promise. The children’s online safety industry is evolving, and many of the technologies we reviewed were point solutions rather than broad attempts to address the children’s safety online as a whole. There is, however, a great deal of innovation in this arena as well as passionate commitment to finding workable, reasonable solutions from companies both large and small. Thus, the TAB emerged from its review process encouraged by the creativity and productivity apparent in this field.
By the end of the review process, the TAB ultimately determined that no single technology reviewed could solve every aspect of online safety for minors, or even one aspect of it one hundred percent of the time. But clearly there is a role for technology in addressing this issue both now and in the future, and most likely, various technologies could be leveraged together to address the challenges in this arena.
Some critics may object to the use of technology as a solution, given the risk of failure and lack of total certainty around performance. However, the TAB believes that although it is indeed true that even the cleverest, most robust technology can be circumvented, this does not necessarily mean that technology should not be deployed at all. It simply means that – even with deployment of the best tools and technologies available to jumpstart the process of enhancing safety for minors online – there is no substitute for a parent, caregiver, or other responsible adult actively guiding and supporting a child in safe Internet usage. Likewise, education is an essential part of the puzzle. Even the best technology or technologies should be only part of a broader solution to keeping minors safer online.
Makes sense to me…
From a personal perspective, I’d like to thank the task force for giving me the opportunity to describe how Information Cards can be used to convey verified claims about individuals, and to thank IDology and Novell for making this real with a working demo of verified age cards for the task force.
I also enjoyed working with Jules Cohen and Chuck Cosson of Microsoft’s Trustworthy Computing and Law and Corporate Affairs groups on the identity technology aspects of Microsoft’s inputs to the task force. I have enormous respect for the balanced and thoughtful perspectives they brought to the discussion, as exemplified by their paper Digital Playgrounds: Creating Safer Online Environments for Children, which was submitted to the task force. Their proposal that existing offline identity proofing ceremonies could be leveraged to enhance safety online resonated with many of the task force members.
I expect media and blog coverage of the report to be active over the next few days. An early sampling includes:
These are important and interesting issues. It’s a discussion well worth following and participating in.
I wanted to bring your attention to two whitepapers covering important Internet identity topics that were published by members of Microsoft’s Trustworthy Computing and Privacy teams, both announced on the blog The Data Privacy Imperative.
The first is “Online Identity Theft: Changing the Game — Protecting Personal Information on the Internet” by Jules Cohen, Brendon Lynch, and other members of Microsoft’s Trustworthy Computing team. Per the announcement, the paper:
… for the first time describes in detail Microsoft’s comprehensive strategy for curbing online identity theft. In addition to describing current Microsoft initiatives, the paper outlines long-term solutions for “changing the game” by ending reliance on “shared secrets” for authentication.
Relying on “shared secrets,” such as usernames, passwords, birthdates and government ID numbers to establish the right to do something online, creates security problems because they are relatively easy to steal and can be difficult to remember, update and manage. We need to employ new identity practices online that are just as reliable but better protect against fraud and abuse, and that’s where Information Cards come in …
The paper has been greeted by favorable reviews, including an Information Week article that also describes the role that the Information Card Foundation can play and a NetworkWorld article by Dave Kearns that concludes “Download this important paper, read it, then act on it.”
The second is “Digital Playgrounds: Creating Safer Online Environments for Children” by Jules Cohen of Microsoft’s Trustworthy Computing team and Chuck Cosson, Policy Counsel on privacy and safety issues, with some input from me. The paper was presented to the Internet Safety Technical Task Force (ISTTF) by Jules and submitted by Microsoft as input to the task force. As Jules wrote about the approach:
The Digital Playgrounds paper outlines a framework that would enable the creation of optional online “walled gardens,” specifically for children and trusted adults. These online sites would only be accessible by folks with trusted and age verified ‘digital identities.’ This framework suggests achieving this by allowing trusted offline parties, who have the ability to meet with a parent and child in real life, examine the appropriate documents and then issue extremely secure digital identities based on these in in-person proofing moments. The framework we have outlined is largely a technical solution to the age verification challenge, but we believe that the nontechnical aspects of the problem will be as difficult to solve as the technical ones, if not more so. For example, government and industry will need to work together on designing the necessary criteria for in-person proofing events as well as the subsequent issuing, auditing and revoking of these digital identity cards.
I especially encourage people to consider the possibility that existing offline identity proofing ceremonies might be leveraged to enhance safety online as well.
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