# Copyright 2019 Huawei Technologies Co., Ltd
#
# 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.
"""
Natural Adversarial Defense.
"""
from ..attacks.gradient_method import FastGradientSignMethod
from .adversarial_defense import AdversarialDefenseWithAttacks
[文档]class NaturalAdversarialDefense(AdversarialDefenseWithAttacks):
"""
Adversarial training based on FGSM.
Reference: `A. Kurakin, et al., "Adversarial machine learning at scale," in
ICLR, 2017. <https://arxiv.org/abs/1611.01236>`_.
Args:
network (Cell): A MindSpore network to be defensed.
loss_fn (Union[Loss, None]): Loss function. Default: ``None``.
optimizer (Cell): Optimizer used to train the network. Default: ``None``.
bounds (tuple): Upper and lower bounds of data. In form of (clip_min,
clip_max). Default: ``(0.0, 1.0)``.
replace_ratio (float): Ratio of replacing original samples with
adversarial samples. Default: ``0.5``.
eps (float): Step size of the attack method(FGSM). Default: ``0.1``.
Examples:
>>> from mindspore.nn.optim.momentum import Momentum
>>> import mindspore.ops.operations as P
>>> from mindarmour.adv_robustness.defenses import NaturalAdversarialDefense
>>> class Net(nn.Cell):
... def __init__(self):
... super(Net, self).__init__()
... self._softmax = P.Softmax()
... self._dense = nn.Dense(10, 10)
... self._squeeze = P.Squeeze(1)
... def construct(self, inputs):
... out = self._softmax(inputs)
... out = self._dense(out)
... out = self._squeeze(out)
... return out
>>> net = Net()
>>> lr = 0.001
>>> momentum = 0.9
>>> batch_size = 16
>>> num_classes = 10
>>> loss_fn = nn.SoftmaxCrossEntropyWithLogits(sparse=False)
>>> optimizer = Momentum(net.trainable_params(), learning_rate=lr, momentum=momentum)
>>> nad = NaturalAdversarialDefense(net, loss_fn=loss_fn, optimizer=optimizer)
>>> inputs = np.random.rand(batch_size, 1, 10).astype(np.float32)
>>> labels = np.random.randint(10, size=batch_size).astype(np.int32)
>>> labels = np.eye(num_classes)[labels].astype(np.float32)
>>> loss = nad.defense(inputs, labels)
"""
def __init__(self, network, loss_fn=None, optimizer=None,
bounds=(0.0, 1.0), replace_ratio=0.5, eps=0.1):
attack = FastGradientSignMethod(network,
eps=eps,
alpha=None,
bounds=bounds,
loss_fn=loss_fn)
super(NaturalAdversarialDefense, self).__init__(
network,
[attack],
loss_fn=loss_fn,
optimizer=optimizer,
bounds=bounds,
replace_ratio=replace_ratio)