diff --git a/tensorflow_privacy/privacy/analysis/compute_noise_from_budget.py b/tensorflow_privacy/privacy/analysis/compute_noise_from_budget.py index 6ae991d..bb23eea 100644 --- a/tensorflow_privacy/privacy/analysis/compute_noise_from_budget.py +++ b/tensorflow_privacy/privacy/analysis/compute_noise_from_budget.py @@ -18,12 +18,13 @@ The script applies the RDP accountant to estimate privacy budget of an iterated Sampled Gaussian Mechanism. The mechanism's parameters are controlled by flags. Example: - compute_dp_sgd_privacy + compute_noise_from_budget --N=60000 \ --batch_size=256 \ --epsilon=2.92 \ --epochs=60 \ - --delta=1e-5 + --delta=1e-5 \ + --min_noise=1e-6 The output states that DP-SGD with these parameters should use a noise multiplier of 1.12. @@ -50,6 +51,7 @@ flags.DEFINE_integer('batch_size', None, 'Batch size') flags.DEFINE_float('epsilon', None, 'Target epsilon for DP-SGD') flags.DEFINE_float('epochs', None, 'Number of epochs (may be fractional)') flags.DEFINE_float('delta', 1e-6, 'Target delta') +flags.DEFINE_float('min_noise', 1e-5, 'Minimum noise level for search.') def main(argv): @@ -60,7 +62,7 @@ def main(argv): assert FLAGS.epsilon is not None, 'Flag epsilon is missing.' assert FLAGS.epochs is not None, 'Flag epochs is missing.' compute_noise(FLAGS.N, FLAGS.batch_size, FLAGS.epsilon, - FLAGS.epochs, FLAGS.delta) + FLAGS.epochs, FLAGS.delta, FLAGS.min_noise) if __name__ == '__main__': diff --git a/tensorflow_privacy/privacy/analysis/compute_noise_from_budget_lib.py b/tensorflow_privacy/privacy/analysis/compute_noise_from_budget_lib.py index 1d8b107..96032f2 100644 --- a/tensorflow_privacy/privacy/analysis/compute_noise_from_budget_lib.py +++ b/tensorflow_privacy/privacy/analysis/compute_noise_from_budget_lib.py @@ -45,7 +45,7 @@ def apply_dp_sgd_analysis(q, sigma, steps, orders, delta): return eps, opt_order -def compute_noise(n, batch_size, target_epsilon, epochs, delta): +def compute_noise(n, batch_size, target_epsilon, epochs, delta, noise_lbd): """Compute noise based on the given hyperparameters.""" q = batch_size / n # q - the sampling ratio. if q > 1: @@ -54,10 +54,11 @@ def compute_noise(n, batch_size, target_epsilon, epochs, delta): list(range(5, 64)) + [128, 256, 512]) steps = int(math.ceil(epochs * n / batch_size)) - init_noise = 1e-5 # minimum possible noise + init_noise = noise_lbd # minimum possible noise init_epsilon, _ = apply_dp_sgd_analysis(q, init_noise, steps, orders, delta) - if init_epsilon < target_epsilon: # 1e-5 was an overestimate + if init_epsilon < target_epsilon: # noise_lbd was an overestimate + print("min_noise too large for target epsilon.") return 0 cur_epsilon = init_epsilon diff --git a/tensorflow_privacy/privacy/analysis/compute_noise_from_budget_test.py b/tensorflow_privacy/privacy/analysis/compute_noise_from_budget_test.py index f2dd635..c8a5a98 100644 --- a/tensorflow_privacy/privacy/analysis/compute_noise_from_budget_test.py +++ b/tensorflow_privacy/privacy/analysis/compute_noise_from_budget_test.py @@ -26,14 +26,15 @@ from tensorflow_privacy.privacy.analysis import compute_noise_from_budget_lib class ComputeNoiseFromBudgetTest(parameterized.TestCase): @parameterized.named_parameters( - ('Test0', 60000, 150, 0.941870567, 15, 1e-5, 1.3), - ('Test1', 100000, 100, 1.70928734, 30, 1e-7, 1.0), - ('Test2', 100000000, 1024, 5907984.81339406, 10, 1e-7, 0.1), + ('Test0', 60000, 150, 0.941870567, 15, 1e-5, 1e-5, 1.3), + ('Test1', 100000, 100, 1.70928734, 30, 1e-7, 1e-6, 1.0), + ('Test2', 100000000, 1024, 5907984.81339406, 10, 1e-7, 1e-5, 0.1), + ('Test3', 100000000, 1024, 5907984.81339406, 10, 1e-7, 1, 0), ) def test_compute_noise(self, n, batch_size, target_epsilon, epochs, - delta, expected_noise): + delta, min_noise, expected_noise): target_noise = compute_noise_from_budget_lib.compute_noise( - n, batch_size, target_epsilon, epochs, delta) + n, batch_size, target_epsilon, epochs, delta, min_noise) self.assertAlmostEqual(target_noise, expected_noise) if __name__ == '__main__':