Secure biometric authentication with client-side feature extraction

Provided is a process that includes: receiving, with a first device, a request to authenticate a user; obtaining, with the first device, an unstructured-data authentication input; extracting, with the first computing device, a plurality of features of the unstructured-data authentication input to form a structured-data representation; determining, with the first device, a first instance of a value that deterministically varies; and determining, with the first device, a first encrypted value based on both the structured-data representation and the first instance of the value that deterministically varies; and sending, with the first device, the first encrypted value to a second computing device.