Re: [OAUTH-WG] JWT Secured Authorization Request (JAR): signing

Benjamin Kaduk <kaduk@mit.edu> Wed, 15 January 2020 20:32 UTC

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Date: Wed, 15 Jan 2020 12:32:45 -0800
From: Benjamin Kaduk <kaduk@mit.edu>
To: George Aristy <george.aristy@gmail.com>
Cc: oauth@ietf.org
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Subject: Re: [OAUTH-WG] JWT Secured Authorization Request (JAR): signing
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On Tue, Jan 14, 2020 at 04:29:39PM -0500, George Aristy wrote:
> Hello everyone.
> 
> Is it possible to relax the requirement to sign the claims set if an
> authenticated encryption mode with prior shared secrets is used? Eg.
> https://tools.ietf.org/html/draft-madden-jose-ecdh-1pu-02. This would
> reduce the size of the request object substantially.

It seems fairly late in the publication process to make such a change,
since the properties provided by digital signature and AEAD tag are subtly
different, and the key-management lifecycle needed to provide secure
operation is different.

That said, off the top of my head, I don't know of anything that would
prevent this functionality from being specified as an extension to plain
JAR.

-Ben