Maintaining differential privacy for database query results

A method comprising:

• receiving a query for a database, the database comprising user data;
• determining that the query is permitted for the database based at least in part on a privacy policy associated with the database;
• determining that performing the query will not exceed a query budget for the database, the query budget being depleted based at least in part on a number of queries performed on the database;
• and
• when the query is permitted and performing the query will not exceed the query budget, performing the query on the database and providing results from the query.

A system comprising;

• a processor;
• and
• a memory device containing instructions, which when executed by the processor cause the processor to:
• receive a query for a database, the database comprising user data;
• determine that the query is permitted for the database based at least in part on a privacy policy associated with the database;
• when the query is permitted, performing the query on the database and receiving results from the query;
• select a differential privacy algorithm for the results based at least in part on a query type of the query;
• apply the selected differential privacy algorithm to the results to generate differentially private results;
• and
• provide the differentially private results.

A non-transitory computer-readable medium comprising instructions, which when executed by a computing device, cause the computing device to perform operations comprising:

• receiving a query for a database, the database comprising user data;
• determining that performing the query will not exceed a query budget for the database, the query budget being depleted based at least in part on a number of queries performed on the database;
• and
• when the query will not exceed the query budget, performing the query on the database and providing results from the query.