Associated Type: Hash

NOT part of the Activity Streams 2.0 Vocabulary.

Activity objects linking to external content such as audio, image or video files must include a "hash" field for users to validate linked content. The value of this "hash" field must be an array of strings, each representing a hash output using a specific algorithm. AT LEAST ONE hash in the array MUST be one of the supported algorithms, although others may also be used.

Hashes MUST be encoded using the multihash specification, and serialized as a multibase string.

Supported Algorithms

AlgorithmMultihash NameLeading bytes (as varint)ReferenceDSNP Version Added
SHA-256sha2-2560x1220RFC 62341.2.0
BLAKE2bblake2b-2560xa0e40220RFC 76931.2.0


This example gives SHA-256 and BLAKE2b hashes for the PDF version of the DSNP whitepaper.

  "hash": [