Re: [Json-canon] [EXT] Re: Support for a WG

Carsten Bormann <cabo@tzi.org> Tue, 22 January 2019 18:05 UTC

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From: Carsten Bormann <cabo@tzi.org>
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Date: Tue, 22 Jan 2019 19:05:39 +0100
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To: "Struse, Richard J." <rjs@mitre.org>
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Subject: Re: [Json-canon] [EXT] Re: Support for a WG
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Hi Richard,

> On Jan 22, 2019, at 13:31, Struse, Richard J. <rjs@mitre.org> wrote:
> 
> The use case is to enable other standards that use a JSON serialization to be able to count on two objects, each with the same contents, having the same hash value based on their representation in JSON.

Well, that is the technical requirement, but what do you use this property for?

JSON was discovered/presented around 2002 and so far has worked quite well without this property.  What use cases have sprung up that now need it?

I’m asking because for many use cases I have heard, there actually are better technical approaches than canonicalization.  Having said that, CBOR, a data format defined in 2013, does have recommendations for deterministic encoding (“canonicalization”), which turned out to be useful for instance for test scripts.  One thing we found out quickly is that deterministic encoding is dependent on the application concept of equality, so it is hard to define a single variant of it for a serialization used in multiple applications.  One more reason to find out about use cases.

Grüße, Carsten