19. The non-transitory computer-readable storage medium of claim 18 , wherein the query string comprises a blinded query string, and further comprising, prior to transmitting the query string to the first tokenizing authority, applying a blinding function to an unprocessed query string to generate the blinded query string.
19. The non-transitory computer-readable storage medium of claim 18 , wherein the query string comprises a blinded query string, and further comprising, prior to transmitting the query string to the first tokenizing authority, applying a blinding function to an unprocessed query string to generate the blinded query string. 21. The non-transitory computer-readable storage medium of claim 19 , wherein the blinding function comprises a cryptographic hash function.