Signing RDF Graphs

Assuming P < GI < NP, the creation and verification of a digital signature of an arbitrary RDF graph cannot be done in polynomial time. However, it is possible to define a large class of canonicalizable RDF graphs, such that digital signatures for graphs in this class can be created and verified in O(nlog(n)). Without changing its meaning, an arbitrary RDF graph can be nondeterministically pre-canonicalized into a graph of this class, before signing. The techniques in this paper are key enablers for the use of digital signature technology in the Semantic Web.