Re: First version of IETF formatted Multihash spec published

On 08/13/2018 09:42 AM, elf-pavlik@hackers4peace.net wrote:
> Could you possibly explain very shortly how does it compare to RFC 
> 6920 Naming Things with Hashes 
> https://datatracker.ietf.org/doc/rfc6920/

Yes, we've actually used RFC 6920 for many years...

> It seams like both try to address including information about 
> algorithm used and hash length.

You could argue that ni:// is for a different set of use cases than
multihash.

ni:// is useful when you're pointing to things with domain names and
possibly query parameters in them. Things that typically map to HTTP
.well-known URLs. Things that you probably wouldn't copy-paste around, etc.

Multihash is useful when you want a compact, deterministic,
copy-pasteable, binary and human representation of a hash. You get
deterministic with ni://, but you don't get compact, copy-paste, or
binary and human representations at the same time.

For example, let's say I wanted to link to a content addressed document
on a server... I could do this using RFC 6920:

ni://example.com/blake2s-128;slAQCk7G8WKeSSYtcJPi+CoyeA==

... which would be translated to this:

http://example.com/.well-known/ni/blake2s-128/slAQCk7G8WKeSSYtcJPi+CoyeA==

or if I wanted to use a particular file path for URLs with clean
semantics, I'd do this:

https://example.com/documents?id=ni%3A%2F%2F%2Fblake2s-128%3BslAQCk7G8WKeSSYtcJPi%2BCoyeA%3D%3D

Developers may find the ergonomics of the two URLs above problematic.
Now compare the above with using a multihash to solve the same problem:

https://example.com/documents/ZeM3u9YD2obamakRCRczRzJza3

The URL above expresses the same thing that the ni:// value above
expresses... but it's a lot cleaner to work with.

There are a number of other advantages, but hopefully that provides some
idea of why multihashes are typically preferred over ni:// style URLs.

-- manu

-- 
Manu Sporny (skype: msporny, twitter: manusporny, G+: +Manu Sporny)
Founder/CEO - Digital Bazaar, Inc.
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http://manu.sporny.org/2017/w3c-web-payments/

Received on Tuesday, 14 August 2018 02:32:37 UTC