Integrate Asset Multibase-Multihash checksums

[fmigneault]

Description

All outputs assets should include digestMultibase to validate the identified resource integrity (i.e.: has it changed since the proof was created?). For STAC Collections representation, corresponding file:checksum and file:byte_order should also be used.

  "image": {
    "id": "https://university.example.org/images/58473",
    "mediaType": "...",
    "digestMultibase": "zQmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n"
  }

Note

• Multibase: identify any base-encoding format of the data itself
• Multihash: identify the type of the cryptographic hash function used for a hash value or digest

https://www.w3.org/TR/vc-data-integrity/#resource-integrity
If present, the digestMultibase value MUST be a single string value, or an list of string values, each of which is a Multibase-encoded Multihash value.

References

• https://github.com/stac-extensions/file#checksums
• https://www.w3.org/TR/vc-data-integrity/#resource-integrity
• https://www.w3.org/2025/credentials/vcdi/vocab/v2/vocabulary.html#digestMultibase
• https://www.w3.org/TR/cid-1.0/#multibase
• https://www.w3.org/TR/cid-1.0/#multihash
• https://github.com/multiformats/multihash

Relates To

• Support for STAC metadata #103
• Support OGC-API Processes - Part 3: Collection Outputs #683
• Support STAC file:checksum and file:byte_order from digestMultibase. #910