Patent 10990677 was granted and assigned to Microsoft on April, 2021 by the United States Patent and Trademark Office.
In this disclosure, a number of ways that quantum information can be used to help make quantum classifiers more secure or private are disclosed. In particular embodiments, a form of robust principal component analysis is disclosed that can tolerate noise intentionally introduced to a quantum training set. Under some circumstances, this algorithm can provide an exponential speedup relative to other methods. Also disclosed is an example quantum approach for bagging and boosting that can use quantum superposition over the classifiers or splits of the training set to aggregate over many more models than would be possible classically. Further, example forms of k-means clustering are disclosed that can be used to prevent even a powerful adversary from even learning whether a participant even contributed data to the clustering algorithm.