tensorflow_privacy/research/audit_2020/attacks.py

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2021-02-15 17:27:18 -07:00
# Copyright 2020 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# =============================================================================
"""Poisoning attack library for auditing."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import numpy as np
from sklearn.decomposition import PCA
from sklearn.linear_model import LogisticRegression
def make_clip_aware(trn_x, trn_y, l2_norm=10):
"""
trn_x: clean training features - must be shape (n_samples, n_features)
trn_y: clean training labels - must be shape (n_samples, )
Returns x, y1, y2
x: poisoning sample
y1: first corresponding y value
y2: second corresponding y value
"""
x_shape = list(trn_x.shape[1:])
to_image = lambda x: x.reshape([-1] + x_shape)
flatten = lambda x: x.reshape((x.shape[0], -1))
assert np.allclose(to_image(flatten(trn_x)), trn_x)
flat_x = flatten(trn_x)
pca = PCA(flat_x.shape[1])
pca.fit(flat_x)
new_x = l2_norm*pca.components_[-1]
lr = LogisticRegression(max_iter=1000)
lr.fit(flat_x, np.argmax(trn_y, axis=1))
num_classes = trn_y.shape[1]
lr_probs = lr.predict_proba(new_x[None, :])
min_y = np.argmin(lr_probs)
second_y = np.argmin(lr_probs + np.eye(num_classes)[min_y])
oh_min_y = np.eye(num_classes)[min_y]
oh_second_y = np.eye(num_classes)[second_y]
return to_image(new_x), oh_min_y, oh_second_y
def make_backdoor(trn_x, trn_y):
"""
trn_x: clean training features - must be shape (n_samples, n_features)
trn_y: clean training labels - must be shape (n_samples, )
Returns x, y1, y2
x: poisoning sample
y1: first corresponding y value
y2: second corresponding y value
"""
sample_ind = np.random.choice(trn_x.shape[0], 1)
pois_x = np.copy(trn_x[sample_ind, :])
pois_x[0] = 1 # set corner feature to 1
second_y = trn_y[sample_ind]
num_classes = trn_y.shape[1]
min_y = np.eye(num_classes)[second_y.argmax(1) + 1]
return pois_x, min_y, second_y
def make_many_pois(trn_x, trn_y, pois_sizes, attack="clip_aware", l2_norm=10):
"""
Makes a dict containing many poisoned datasets. make_pois is fairly slow:
this avoids making multiple calls
trn_x: clean training features - shape (n_samples, n_features)
trn_y: clean training labels - shape (n_samples, )
pois_sizes: list of poisoning sizes
l2_norm: l2 norm of the poisoned data
Returns dict: all_poisons
all_poisons[poison_size] is a pair of poisoned datasets
"""
if attack == "clip_aware":
pois_sample_x, y, second_y = make_clip_aware(trn_x, trn_y, l2_norm)
elif attack == "backdoor":
pois_sample_x, y, second_y = make_backdoor(trn_x, trn_y)
else:
raise NotImplementedError
all_poisons = {"pois": (pois_sample_x, y)}
for pois_size in pois_sizes: # make_pois is slow - don't want it in a loop
new_pois_x1, new_pois_y1 = trn_x.copy(), trn_y.copy()
new_pois_x2, new_pois_y2 = trn_x.copy(), trn_y.copy()
new_pois_x1[-pois_size:] = pois_sample_x[None, :]
new_pois_y1[-pois_size:] = y
new_pois_x2[-pois_size:] = pois_sample_x[None, :]
new_pois_y2[-pois_size:] = second_y
dataset1, dataset2 = (new_pois_x1, new_pois_y1), (new_pois_x2, new_pois_y2)
all_poisons[pois_size] = dataset1, dataset2
return all_poisons