266 ◾ Secure Data Provenance and Inference Control
1. KB′ = Ans(Q
J
) ∪ Prov(Ans(Q
J
))
If answers are available from fulfilling the request of Q
J
from the set
, it is added to an empty knowledge base and we continue to the next
step. Otherwise, there are no answers for Q
J
. is case is most likely when
it is not possible to release answers after satisfying the constraints from the
privacy policies.
2. KB′ = KB′ ∪ H
Q
e query history is derived from all the queries answered so far (e.g.,
(Q
1
…Q
j−1
)⊢ H
Q
. KB′ is updated from the history.
3. R(KB′) → KB′ + Inf(KB′)
R is a decidable RDFS/OWL reasoner.
e reasoner performs inferencing over the knowledge base to determine
newly inferred triples that are different from those already in the ...