Differential Privacy (Uber/Berkeley)

The GDA Score Project has added an interface for Differential Privacy. Specifically, we have added the open-source DP implementation released by Uber in 2017, which was the result of a collaboration between researchers at UC Berkeley and Uber. That implementation has since been deprecated, and can be found at https://github.com/uber-archive/sql-differential-privacy.

The open-source implementation did not include a budget mechanism. The GDA Score implementation includes a naive budget mechanism that simply subtracts the epsilon value of each query from a total budget. The total budget is specified by the calling code.

A reference implementation of an attack using the Uber DP interface can be found at https://github.com/gda-score/attacks/blob/master/examples/testUberSinglingOut.py.

The following additions were made to the GDA Score gdaAttack interface:

The anonymization type is 'uber_anon', for example:

config = {
    "configVersion": "compact1",
    "basic": {
        "attackType": "Test",
        "criteria": "singlingOut"
    },
    'anonTypes': [['uber_anon']],
    'tables': [['banking', 'accounts']]
}

paramsList = setupGdaAttackParameters(config)
params = paramsList[0]

The budget itself is set in gdaAttack(params) using the new attribute params['db_budget']:

params['dp_budget'] = 5.0
x = gdaAttack(params)

The epsilon for each individual attack query is conveyed in the askAttack(query) call with the new attribute query['epsilon']:

query = {}
sql = """Select count(*)
         from transactions
         where operation = 'VKLAD'
         """
query['sql'] = sql
query['epsilon'] = 1
x.askAttack(query)

The amount of budget remaining after the query is conveyed in the answer provided by the getAttack() call in the attribute reply['remaining_dp_budget']:

reply = x.getAttack()
remaining_budget = reply['remaining_dp_budget']

If the budget was exceeded by the query, the reply contains an error code that includes the phrase ‘Budget Exceeded’:

if 'answer' in reply:
    # Budget not exceeded
    ....
else if 'Budget Exceeded' in reply['error']:
    # Budget is exceeded
    ....
else:
    # Some other error
    ....

All other aspects of the gdaAttack API operate as normal.