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RE: Building a did:key document with a publicKeyJwk

From: Nikos Fotiou <fotiou@aueb.gr>
Date: Fri, 12 Mar 2021 12:45:17 +0200
To: "'David Chadwick'" <D.W.Chadwick@kent.ac.uk>, <public-credentials@w3.org>
Message-ID: <00a001d7172c$cab1aa80$6014ff80$@aueb.gr>
We had a similar issue, we wanted to use base64url encoded ED25519 public keys directly with did:key  In theory this should be supported since did:key uses multibase and at the end this is what we did (internally). Nevertheless, the specifications seem to enforce base58 encoding. I created this issue https://github.com/w3c-ccg/did-method-key/issues/26 but I didn’t receive any response. In retrospect, probably this was not the best place to discuss this issue 😊


From: David Chadwick <D.W.Chadwick@kent.ac.uk> 
Sent: Friday, March 12, 2021 11:33 AM
To: public-credentials@w3.org
Subject: Re: Building a did:key document with a publicKeyJwk


Hi Brent

we already build DID keys using RFC 7517 and I documented this many months ago on the list when did:key was first proposed. I suggested did:key:jwt as the prefix to this method but this was rejected by the did:key authors. Nevertheless we went ahead anyway and we have been using this encoding method successfully in user trials for many months.

I am thinking of simply registering did:jwt as a separate method. The advantage of this method is that canonicalisation is not needed, base64 is used, human reading of the key is never needed or involved so base58 is not necessary.


Kind regards


On 12/03/2021 03:45, Brent Shambaugh wrote:

Dear all,

I am building a did:key document. The base64url for multibase puts a u prefix in front. In my publicKeyJwk I keep the prefix for the x and y coordinates of the key. I've attached some scratch code.


Would it be correct, or incorrect to remove the prefix? I am not sure what to make of RFC7518.

Perhaps since the example with P-256 https://w3c-ccg.github.io/lds-jws2020/ is missing the 

prefix u from https://github.com/multiformats/multibase I need to remove it. 






Received on Friday, 12 March 2021 10:45:36 UTC

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