Cryptography
Resource Description Framework
Also known as: RDF
The W3C data model underlying JSON-LD — statements expressed as subject-predicate-object triples that form a directed graph.
The Resource Description Framework (RDF) is the W3C data model for expressing semantic information. An RDF dataset is a collection of triples or quads: subject-predicate-object (with an optional graph identifier for quads). Each triple makes one factual statement about a resource, and resources are identified by IRIs.
JSON-LD is one serialization of RDF — the JSON-LD @context tells parsers how to expand JSON keys into full IRIs, and the expanded form is equivalent to an RDF graph. N-Quads is another serialization, and URDNA2015 (now RDFC-1.0) canonicalizes RDF datasets to N-Quads deterministically.
For LearnCoin, RDF matters because it's what makes JSON-LD canonical: two credentials that look different in JSON can express the same RDF graph, and URDNA2015 produces the same N-Quads output for both. That deterministic output is the byte input to SHA-256 leaf hashing, which is what makes signature verification possible despite whitespace, key ordering, or @context variations.
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