US Patent 10979426 Privacy-protecting deduplication

A method is disclosed. The method includes a server computer receiving, from a user device, a first encrypted biometric template, wherein the server computer stores a plurality of encrypted enrollment biometric templates, and a table comprising a plurality of encrypted match values and corresponding unencrypted match values. The server computer can then, for each of the plurality of encrypted enrollment biometric templates, input the first encrypted biometric template and an encrypted enrollment biometric template into a function to obtain an encrypted match value. The server computer can then, for each of the plurality of encrypted enrollment biometric templates, determine if the encrypted match value corresponds to an unencrypted match value using the table, wherein the unencrypted match value is greater than a threshold. The server computer can then provide a notification to the user device or another device associated with the unencrypted match value.