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Re: [Multiformats] New versions of Multibase and Multihash published

Manu Sporny <msporny@digitalbazaar.com> Sun, 20 August 2023 15:24 UTC

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From: Manu Sporny <msporny@digitalbazaar.com>
Date: Sun, 20 Aug 2023 11:23:55 -0400
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To: Melvin Carvalho <melvincarvalho@gmail.com>
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Subject: Re: [Multiformats] New versions of Multibase and Multihash published
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On Sun, Aug 20, 2023 at 10:57 AM Melvin Carvalho
<melvincarvalho@gmail.com> wrote:
> Is it back compat (ie using the same string of characters) with the widely used CID format?

The short answer is "yes, almost certainly".

If by "widely used CID format", you mean the Multicodec headers 0x01,
0x02 and 0x03, then yes, nothing in these specifications prevent the
usage of those headers in a Multibase-encoded value and the Multihash
value headers don't conflict with the CID value headers.

However...

> Can I turn a CID into a URI and what would that look like?
>
> mh://<cid>
>
> ni://mh/<cid>
>
> Something like this?

No, because CIDs are not file hashes, so you can't just use Multihash for them:

https://docs.ipfs.tech/concepts/content-addressing/#cids-are-not-file-hashes

IOW, nothing we're doing here precludes encoding a CID in a Multibase
value... but CIDs (all versions of them) contain more information than
just the content hash itself (which is all Multihash encodes). We are
not standardizing CIDs at this point in time, but we're not precluding
their usage or future standardization, either.

-- manu

-- 
Manu Sporny - https://www.linkedin.com/in/manusporny/
Founder/CEO - Digital Bazaar, Inc.
https://www.digitalbazaar.com/

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