The Dataspace Protocol is a set of specifications designed to facilitate interoperable data sharing between entities governed by usage control and based on Web technologies. These specifications define the schemas and protocols required for entities to publish data, negotiate Agreements, and access data in a data space
dspace:checksum
is used in the example here: https://github.com/International-Data-Spaces-Association/ids-specification/blob/main/negotiation/message/contract-negotiation.json but not in the http binding here: https://github.com/International-Data-Spaces-Association/ids-specification/blob/main/negotiation/contract.negotiation.binding.https.md#241-getand it seems it is not described anywhere in the document. At least I couldn't find it with git grep.
Matthias Binzer