Patent ID: 8607350

Claim:
A computer-implemented method for secure distributed query processing, comprising: storing data tables from at least one data provider in at least one first computer comprising a sovereign server; performing encrypted input and output of said data tables between said server and a second computer; computing join operations, comprising determining whether arbitrary join predicates yield matches within said data tables; outputting encrypted results of said join operations, where said data tables include database relations A, B, C and D, where |A|=|C|, and |B|=|D|, where A and C have identical schema, and B and D have identical schema, where for any given maximum number of tuples from B that match a tuple from A, J AC , and J BD are ordered lists of server locations read and written by the sovereign server during the join of A with respect to C, and the joint of B with respect to D, respectively, and where J AC and J BD are identically distributed.