Calculating differentially private queries using local sensitivity on time variant databases

A system for enhancing the determination of differential privacy query results, the system comprising:

• a database;
• a result cache;
• one or more processors;
• and
• a computer-readable data storage device storing program instructions that, when executed by the one or more processors, cause the system to perform operations comprising:
• obtaining a first query of the database;
• determining that a specificity of the first query exceeds a specificity threshold;
• determining that the result cache lacks any query results of previous queries that are substantially equivalent to the first query;
• partitioning the database into a plurality of groups;
• determining a query result by executing the first query on the plurality of groups;
• determining a sensitivity of the query and a nominal measurement of the query;
• determining a noisy result by adding noise to the query result based on the sensitivity of the query and the nominal measurement of the query;
• storing the noisy result in the result cache with a hash value generated using the first query, the sensitivity of the query, and the nominal measurement of the query;
• providing the noisy result in response to the first query;
• and
• maintaining the noisy result in the result cache for a predetermined period of time for providing in response to one or more subsequently obtained queries of the database based on the hash value and a second hash value of the one or more subsequently obtained queries.