1. A method comprising: transmitting one or more secure dot product matching protocols and initial secure dot product data generated from a document thumbprint for a document to a remote system, wherein the initial secure dot product data is a secure key computed from one or more mixed-media bounding box codes corresponding to one or more visual features extracted from the document and one or more random parameters generated for a secure dot product process, and wherein the one or more secure dot product matching protocols adjust one or more of the one or more random parameters for document matching, and a first secure dot product matching protocol transmitted to the remote system with the initial secure dot product data is selected by a client to reduce a size of the secure key from an initial size to a reduced size; receiving a response from the remote system, the response generated by the remote system utilizing the initial secure dot product data and without knowledge of the document, the response generated by the remote system against a database of potential matching document thumbprints corresponding to a plurality of documents based on the one more secure dot product matching protocols, the document thumbprints ordered by the remote system based on a probability that corresponding documents will be copied by the client, the thumbprints ordered in the database prior to the remote system's receipt of the transmitted initial secure dot product data; and determining whether the response indicates a match for the document.