[dispatch] Finding a home for Multibase and Multihash

[Manu Sporny <[e-mail]>]

Dearest Majestys of Dispatching Things at IETF,

We would like to work towards publishing a few of the "Multiformats"
specifications as IETF RFCs. The Multiformats Project[1] describes a
collection of byte headers that are prepended to data values. These
headers aim to future-proof data values in a representation-agnostic
manner such that they can be used across a variety of data formats
such as JSON, CBOR, and YAML. The approach is used in systems such as
IPFS[2], W3C Decentralized Identifiers[3], the Data Integrity[4]
pre-standard (at W3C), and W3C Verifiable Credentials[5]. Multiformats
enable interoperability and agility at the data format layer.

To more narrowly focus on two classes of Multiformats, we'd like to
find a home for Multibase[6] and Multihash[7], to start.

The Multibase[6] specification prepends an ASCII byte to a
base-encoded value such that a processor can look at the first byte to
determine the base encoding of the rest of the string.

The Multihash[7] specification prepends a variable-length integer
which expresses a particular type of cryptographic hash (e.g., SHA-2,
256-bit value), to a cryptographic hash value such that a processor
can look at the header to determine what the value bytes represent.

Multibase and Multihash can be combined to provide multibase-encoded
multihash values.

The Multibase data format is used by:

* IPFS[2] to encode data values used by protocols on the network,
* W3C Decentralized Identifier[3] Methods to base-encode binary
identifiers and cryptographic public key values,
* W3C Verifiable Credentials[5] to base-encode cryptographic signature values,
* The `proofValue` Data Integrity[4] pre-standard (at W3C),
* The `proofValue` in the 2020 Ed25519 Cryptosuite[10] pre-standard (at W3C),
* The `proofValue` in the 2019 ECDSA Cryptosuite[11] pre-standard (at W3C).

The Multihash data format is used by:

* IPFS[2] to identify content on the network,
* An addition to W3C Verifiable Credentials for referencing external
content by hash.
* The Cryptographic Hyperlinks I-D[12] to provide content integrity
protection for URLs.

There exist 14 implementations[13] for Multibase, and 18
implementations for Multihash[14].

Which places at IETF would be appropriate homes for these two
specifications, noting that we will most likely want to standardize
other Multiformats specifications at IETF in the future?

-- manu (Digital Bazaar), bengo (Protocol Labs), and aaron (Project Bluesky)

[1]: https://multiformats.io/
[2]: https://ipfs.io/
[3]: https://www.w3.org/TR/did-core/
[4]: https://w3c.github.io/vc-data-integrity/
[5]: https://www.w3.org/TR/vc-data-model/
[6]: https://datatracker.ietf.org/doc/html/draft-multiformats-multihash-04
[7]: https://datatracker.ietf.org/doc/html/draft-multiformats-multibase-05
[8]: https://w3c-ccg.github.io/data-integrity-spec/
[9]: https://w3c.github.io/vc-wg-charter/
[10]: https://w3c-ccg.github.io/di-eddsa-2020/
[11]: https://w3c-ccg.github.io/di-ecdsa-secpr1-2019/
[12]: https://datatracker.ietf.org/doc/html/draft-sporny-hashlink-07
[13]: https://github.com/multiformats/multibase#implementations
[14]: https://multiformats.io/multihash/#implementations

-- 
Manu Sporny - https://www.linkedin.com/in/manusporny/
Founder/CEO - Digital Bazaar, Inc.
News: Digital Bazaar Announces New Case Studies (2021)
https://www.digitalbazaar.com/