System for restrictive discovery of private data feature intersection

A privacy-protecting data-sharing method comprising:

• receiving an encryption key and a first partial decryption key reference corresponding to the encryption key;
• generating a listing of homomorphically encrypted requestor descriptors by encrypting a requestor dataset using the encryption key and using a predefined homomorphic encryption algorithm;
• sending the listing of homomorphically encrypted requestor descriptors to a data source;
• receiving a list-matching indicator encrypted using the predefined homomorphic encryption algorithm from the data source indicating an overlap between the requestor dataset and a comparer dataset at the data source;
• requesting and receiving a second partial decryption key reference corresponding to the encryption key from the data source;
• generating a decryption key corresponding to the encryption key from the first partial decryption key reference and the second partial decryption key reference;
• decrypting the list-matching indicator that is homomorphically encrypted to generate a decrypted list-matching indicator using the decryption key;
• and
• identifying a subset of data items of the comparer dataset as matching the requestor dataset according to the decrypted list-matching indicator.

A system comprising:

• a memory circuitry for storing computer instructions;
• a network interface circuitry;
• and
• a processor in communication with the network interface circuitry and the memory circuitry, the processor configured to execute the computer instructions to:
• receive an encryption key and a partial decryption key reference corresponding to the encryption key;
• receive a listing of homomorphically encrypted requestor descriptors from a requesting device, the listing of homomorphically encrypted requestor descriptors generated by the requesting device using the encryption key and using a predefined homomorphic encryption algorithm applied to a requestor dataset;
• retrieve an original comparer dataset;
• extract textual data features or description data items from the original comparer dataset;
• expand the textual data features or description data items to include additional words or phrases;
• generate a requestor dataset by numericizing the expanded textual data features or description data items;
• generate a list-matching indicator indicating an overlap between the requestor dataset and the listing of homomorphically encrypted requestor descriptors;
• encrypt the list-matching indicator to generate a homomorphically encrypted list-matching indicator using the predefined homomorphic encryption algorithm;
• send the homomorphically encrypted list-matching indicator to the requesting device;
• and
• in response to a key reference request from the requesting device, send the partial decryption key reference to the requesting device.