GraphChain: A Distributed Database with Explicit Semantics and Chained RDF Graphs

In this paper we present a new idea of creating a Blockchain compliant distributed database which exposes its data with explicit semantics, is easily and natively accessible, and which applies Blockchain securitization mechanisms to the RDF graph data model directly, without additional packaging or specific serialisation. Essentially, the resulting database forms the linked chain of named RDF graphs and is given a name: GraphChain. Such graphs can then be published with the help of any standard mechanisms using triplestores or as linked data objects accessible via standard web mechanisms using the HTTP protocol to make them available on the web. They can also be easily queried using techniques like SPARQL or methods typical to available RDF graphs frameworks (like rdflib, Apache Jena, RDF4J, OWL API, RDF HDT, dotnetRDF and others). The GraphChain concept comes with its own, OWL-compliant ontology that defines all the structural, invariant elements of the GraphChain and defines their basic semantics. The paper describes also a few simple, prototypical GraphChain implementations with examples created using Java, .NET/C# and JavaScript/Node.js frameworks.