[Multiformats] IETF 116 Dispatch Multiformats: Responses to Jonathan Rosenberg

[Manu Sporny <[e-mail]>]

Jonathan Rosenberg said:
> I was surprised there was no magic cookie in front of these Multiformats, it collides with UU-encoded strings, is this a specific domain encoding or something meant for global use? Is there a reason there is no magic cookie in front of it?

If I understand your question correctly, Multiformats are not designed
to be a replacement for magic bytes in file headers or as a
replacement for things like uuencoding.

They are meant to be used in application-specific data structures
expressed in syntaxes like JSON, YAML, and CBOR. In other words, there
is always an encapsulating data model that signals that the value is a
Multiformat. For example, in JSON

{
  "url": "https://foo.example/file.dat",
  "digestMultibase": "zjEkl...Wkd"
}

One could imagine that the JSON object above is identifying a file by
a URL and then associating a Multibase encoded digest value
(presumably encoded as a Multihash value). The specification
associated with that JSON object would state clearly what Multibase
and Multihash combinations are expected/allowed.

Therefore, I believe that the answer to your question is: "There is no
magic cookie in front of it because Multiformats are always used where
the fact that the value is a Multiformat value is known before the
value is consumed. Multiformats are not a replacement for magic bytes
in file headers or uuencoding."

Did that answer your question, Jonathan?

-- manu

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