1. A computer implemented method for identifying a sketching matrix used by a linear sketch comprising: receiving, by a processor, an initial output of the linear sketch; generating, by the processor, a query vector; inputting, by the processor, the query vector into the linear sketch; receiving, by the processor, an revised output of the linear sketch based on inputting the query vector; iteratively repeating the steps of generating the query vector, inputting the query vector into the linear sketch, and receiving an revised output of the linear sketch based on inputting the query vector until the sketching matrix used by the linear sketch can be identified.
1. A computer implemented method for identifying a sketching matrix used by a linear sketch comprising: receiving, by a processor, an initial output of the linear sketch; generating, by the processor, a query vector; inputting, by the processor, the query vector into the linear sketch; receiving, by the processor, an revised output of the linear sketch based on inputting the query vector; iteratively repeating the steps of generating the query vector, inputting the query vector into the linear sketch, and receiving an revised output of the linear sketch based on inputting the query vector until the sketching matrix used by the linear sketch can be identified. 5. The method of claim 1 , wherein the query vector is selected from a query distribution that is a Gaussian distribution having a varying covariance structure.