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Mike,</div><div dir="ltr"><br></div><div dir="ltr">Thanks for writing down your thoughts, very helpful! I’ve spent time thinking about, and have had discussions about your post script:</div><div dir="ltr"><br></div><blockquote style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(155,155,155)!important;padding-left:1ex;color:rgb(155,155,155)!important" class="gmail_quote" type="cite"><div dir="ltr" style="orphans: auto; widows: auto;"><span style="font-family:inherit;font-size:17.85px;color:rgb(17,17,17)!important">When a verifier needs multiple credentials, they may be in different wallets. If the verifier tries to make a PE request for multiple credentials that are spread between wallets, will it always fail because no single wallet can satisfy it?</span></div></blockquote><div><br></div><div dir="ltr"><br></div>My answer to our team internally has been “yes it will fail.” PE was designed in a weird spot between a data model and a protocol, maybe more accurately described as a <i>data model for a protocol</i>, but it has left out a few pieces of the data model that would make it even more useful for a robust protocol. <div><br></div><div>To mitigate in the short term, we are going with multiple finer-grained PE requests; however, there’s still the question of how a wallet can communicate with a verifier that they need a single request broken up into N pieces—that’s part 1 of what’s missing in the data model.</div><div><br></div><div dir="ltr">There’s another problem, too—what happens if a wallet does not have the credential(s) they need, where do they go and get them? In the OID4VC world we could leverage an issuer’s well known endpoints to discover the credential’s they offer, but it may be more useful to encode this information directly in PE as a part of a “discovery” request. Especially useful in cases where the verifier is not the issuer of the credentials being requested.</div><div dir="ltr"><br></div><div dir="ltr">I’d like to see two additions to PE:</div><div dir="ltr"><br></div><div dir="ltr"><ul dir="ltr" style="list-style-type:"\002013 ";margin:0px"><li>A new data object that enables a wallet to communicate how many submission’s they’ll make against a single presentation request (multi-part) OR a way for a wallet to specify they need N presentation requests (while also specifying which input descriptors/submission requirements they’ll fulfill for each).</li><li>A new data object for a verifier to advertise where a wallet can obtain the credentials they’re requesting</li></ul><div><br></div><div dir="ltr">And in a protocol (OID4VP):</div><div dir="ltr"><ul style="list-style-type:"\002013 ";margin:0px" dir="ltr"><li>The ability to support multi-step presentations including a negotiation step with wallets</li><li>(Possibly) A well known endpoint for a verifier to advertise the credentials they trust, for which purpose, from different issuers, and where to get them (perhaps similar to the work we started on <a href="https://identity.foundation/trust-establishment/">DIF Trust Establishment</a>)</li></ul><div><br></div><div dir="ltr">PE needs other changes too, as you called out. I had a few conversations at IIW which made me think PEv3 may be need to be started sooner, rather than later, and this group may be the right place to do it.</div><div dir="ltr"><br></div><div dir="ltr">Gabe</div></div><div><br class="Apple-interchange-newline">
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<div dir="ltr" class="gmail_attr">On Oct 14, 2023 at 6:11:18 PM, Michael Jones via Openid-specs-digital-credentials-protocols <<a href="mailto:openid-specs-digital-credentials-protocols@lists.openid.net">openid-specs-digital-credentials-protocols@lists.openid.net</a>> wrote:<br></div>
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<p class="MsoNormal">I thought I’d share my write-up of the Presentation Exchange session at IIW for those of you who couldn’t be there.</p>
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<p class="MsoNormal">See <a href="https://self-issued.info/?p=2427">https://self-issued.info/?p=2427</a>.</p>
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<p class="MsoNormal"> -- Mike</p>
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-- <br>Openid-specs-digital-credentials-protocols mailing list<br><a href="mailto:Openid-specs-digital-credentials-protocols@lists.openid.net">Openid-specs-digital-credentials-protocols@lists.openid.net</a><br><a href="https://lists.openid.net/mailman/listinfo/openid-specs-digital-credentials-protocols">https://lists.openid.net/mailman/listinfo/openid-specs-digital-credentials-protocols</a><br>
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