Seeking feedback: WebAuthn to Pay proposed flows

Hi Payments WG,

I'd like to get your feedback on the proposed WebAuthn to Pay (aka Secure
Payment Confirmation) pilot [1]. The goal of this pilot is to prototype an
enhancement of the 3DS step-up flow (direct user authentication with the
issuer during checkout using WebAuthn without redirect) and evaluate the
user friction and conversion impact of such a flow.

The finalized UX mocks [2] were discussed at today's WebAuthn/WPWG Joint
Task Force call [3].

For the WPWG call this coming Thursday, July 23rd, I'll do a walk-through
of the sequence diagrams [4][5]. I look forward to your feedback.

If you have any questions, please reach out to myself and my collaborators
on this proposal: Benjamin Tidor (btidor@stripe.com), and Adrian
Hope-Bailie (adrian@coil.com).

Thanks!
Danyao, on behalf of the WebAuthn to Pay collaborators

[1] WebAuthn to Pay pilot overview:
https://bit.ly/webauthn-to-pay-2020h2-pilot
[2] WebAuthn to Pay UX mocks: https://bit.ly/webauthn-to-pay-2020h2-pilot-ux
[3] July 21 WebAuthn / WPWG Joint Task Force minutes:
https://www.w3.org/2020/07/21-webauthn-pay-minutes
[4] Enrollment sequence diagram:
https://bit.ly/webauthn-to-pay-2020h2-pilot-enrollment
[5] Checkout sequence diagram:
https://bit.ly/webauthn-to-pay-2020h2-pilot-checkout