A device, system and method for anonymously comparing query images to reference images is provided. A computing device receives, from at least one camera, a query image. The computing device generates a query characteristic vector associated with the query image. The computing device applies a mathematical operator on the query characteristic vector to obtain a query vector. The computing device compares the query vector to a reference vector, the reference vector obtained by applying a complementary mathematical operator on a reference characteristic vector associated with a reference image, the complementary mathematical operator comprising a complement of the mathematical operator. The computing device, in response to the comparing indicating a match between the query vector and the reference vector, provides a notification of the match.