Patent ID: 8285748

Claim:
A computer-implemented method for controlling access to sensitive information, the method comprising: maintaining access constraint data that can be used to control access to said sensitive information; wherein said access constraint data comprises match pattern data and apply pattern data; wherein said match pattern data represents a semantic graph pattern expression that identifies one or more basic semantic graphs of a semantic graph of said sensitive information; wherein said apply pattern data represents a semantic graph pattern expression to be evaluated against any basic semantic graph of the one or more basic semantic graphs before the any basic semantic graph is returned as a query result; receiving a semantic query requesting access to said sensitive information; wherein said semantic query is capable of being evaluated against a semantic graph of said sensitive information; based on said match pattern data, determining whether said semantic query should be constrained according to said apply pattern data; responsive to determining that said semantic query should be constrained according to said apply pattern data, rewriting said semantic query according to said apply pattern data to produce a rewritten query; executing said rewritten query against a database that contains said sensitive information; and returning any results of executing said rewritten query.