Dual deep learning architecture for machine-learning systems

A method in which one or more processing devices of an authentication server system perform operations comprising:

• receiving, from a client computing system, an authentication query that includes an unstructured input data object as a query parameter;
• servicing the authentication query by matching the unstructured input data object to an unstructured reference data object stored in a memory device of the authentication server system, wherein matching the unstructured input data object to the unstructured reference data object comprises:
• providing the unstructured input data object to a dual deep learning network having an embedding subnetwork and a relationship subnetwork, wherein outputs from an output layer of the embedding subnetwork are provided as inputs to the relationship subnetwork via an input layer of the relationship subnetwork;
• generating, by the embedding subnetwork, an input feature vector from the unstructured input data object, wherein the embedding subnet is trained to generate, from unstructured training data objects, training feature vectors based on a minimization of a loss function for a feature learning objective,
• providing, from the output layer of the embedding subnetwork to the input layer of the relationship subnetwork, the input feature vector and a reference feature vector computed by applying the embedding subnetwork to the unstructured reference data object, wherein the relationship subnetwork is trained, with relationship training feature vectors generated by the embedding subnetwork, to output probabilities of pairs of the relationship training feature vectors belonging to common classes, and
• generating an output probability of the unstructured input data object and the unstructured reference data object belonging to a common class by applying the relationship subnetwork to the input feature vector and the reference feature vector;
• and
• transmitting, to the client computing system, a responsive message to the authentication query that is generated from the output probability, wherein the responsive message is configured for causing the client computing system to grant or deny access to the client computing system by a user device from which the unstructured input data object was obtained.