Patent ID: 8375030

Claim:
A method for determining a differentially private aggregate classifier for a set of databases, wherein each database in the set of databases is associated with a classifier and a noise value, wherein the classifier and the noise value are determined locally for each database, such that a combination of the classifier and the noise value ensure a differential data privacy of the database, and wherein the differentially private aggregate classifier preserves the differential data privacy of each database, comprising the steps of: combining classifiers to determine an aggregate classifier; modifying the aggregate classifier with a noise value corresponding to a smallest database in the set of databases to produce the differentially private aggregate classifier; determining an obfuscated index of the smallest database resulting from a permutation of indexes of the set of databases; selecting obliviously, from additive shares of all noise values, a first additive share of the noise value associated with the smallest database based on the obfuscated index, wherein a second additive share of the noise value is stored in one or more databases; and determining the differentially private aggregate classifier by obliviously combining each classifier, the first and the second additive shares of the noise value, wherein the steps of the method are performed by a processor.