System with privacy-preserving neural graph databases and method for using the same

A system using a privacy-preserving neural graph database for receiving a query from a user and giving an answer to the user in response to the query, comprising:

• a user query input receiver for serving as a user interface to receive a structured query language as a query from a user;
• a graph builder module configured to receive the query from the user query input receiver and configured to construct a computational graph for converting the query into a directed acyclic graph, where edges represent operations on sets of entities and attributes;
• a query encoder model configured to receive a query graph related to the computational graph from the graph builder module for processing the query graph, wherein the query encoder model is configured to convert the query graph into a vector format;
• an answer retrieval module configured to receive the vector format of the query graph from the query encoder model and retrieve candidate answer sets, wherein information output by the answer retrieval module denotes answer sets of entities or values retrieved by the computational graph;
• a privacy risk identifier configured to receive the information output by the answer retrieval module and determine whether the answer sets pose any privacy risks, check for sensitive information, and flag queries that lead to privacy breaches, wherein the privacy risk identifier is further configured to classify the answer sets from the computational graph into a public answer set and a privacy answer set;
• a score calculator engine configured to receive the public answer set and the privacy answer set and calculate a score of each candidate answer by computing probability of the public answer set and the privacy answer set using corresponding loss functions, wherein a low threshold is assigned to a loss function for the public answer set by the score calculator engine, requiring a loss function calculation result for the public answer set to be lower than the threshold, and wherein a high threshold is given to a loss function for the privacy answer set by the score calculator engine, requiring a loss function calculation result for the privacy answer set to be higher than the threshold;
• and
• an answer output module configured to reference results of the loss functions in combination with the threshold values to select a final answer for the original query.