Autozoom-Attack

Codes for reproducing query-efficient black-box attacks in “AutoZOOM: Autoencoder-based Zeroth Order Optimization Method for Attacking Black-box Neural Networks”, published at AAAI 2019 ​​​​​​

Software version

The program is developed under Tensorflow 1.6.0 and Tensorflow-gpu 1.6.0. Note that we use Keras embedded inside Tensorflow. It is highly recommended to use the exact same version of Tensorflow and Tensorflow-gpu

Datasets

The dataset mnist and cifar10 would be downloaded automatically the first time you use them. For the imagenet dataset please download the file using the following link:

ImageNet Test images

ImageNet Test labels

The images and labels are stored with numpy format. Please download them and put them under AutoZOOM folder. We use the class ImageNetDataNp defined under file setup_inception.py to load these two files.

Classifiers

We provide the classifiers for mnist and cifar10 under the folder models. See setup_mnist.py and setup_cifar.py for more information about the classifiers. To obtain the classifier for imagenet run

python3 setup_inception.py

This will download the inception_v3 model pre-trained for imagenet.

Autoencoder

We provide the autoencoder for mnist, cifar10 and imagenet.The naming for encoder and decoder are <dataset>_<compress_mode>_encoder.h5 and <dataset>_<compress_mode>_decoder.h5. The compress_mode is an integer indicating the compression rate of the additive noise (attack space). When compress_mode=1, the width and height are respectively reduced by 1/2 of the original size. For compress_mode=2, its width and height are reduced to 1/4. As for imagenet, the settings are slightly different. Since the original image size for imagenet is 299x299, we first resize the image to 128x128 and then compress the image.

See setup_codec.py for more information about the autoencoder.

Run attacks

Several options can be used to configure the attacks:

Arguments

Attack methods

We provide four kinds of attacking methods: zoo, zoo_ae, autozoom_bilin and autozoom_ae. The method zoo uses the method proposed in ZOO: Zeroth Order Optimization based Black-box Attacks to Deep Neural Networks without Training Substitute Models. For zoo_ae, autoencoders are used to reduce the size of attack space. Random vectors are used in autozoom_bilin for gradient estimation. In autozoom_ae, both autoencoder and random vector are used for efficient blackbox attack. The attack method can be specified using -a or --attack_method.

Batch size

For zoo and zoo_ae, attacks are performed in batch. Use -b or --batch_size to specify the number of pixels updated within one iteration. For autozoom_bilin, autozoom_ae, this option is not valid.

Initial constant and switch iterations

The attacking procedure uses a constant to determine the preference between the likelihood of a success attack and the distortion of the image. A large constant results in fast attack (less iteration) but also indicates large distortion. This constant will be adjusted after several iterations. To specify the initial setting of the constant, use -c or --init_const. The number of iterations to update the constant can be specified using --switch_iterations.

Attack space

For zoo and autozoom_bilin, you can specify the size on the attacking space using --img_resize. For zoo_ae and autozoom_ae the size of the attacking space is defined by the autoencoder.

Dataset

Specify the dataset using -d or --dataset.

Number of images to attack

Use -n or --num_img to specify the number of images to attack. Images that are correctly classified by the classifier would be randomly selected.

Maximum number of iterations

Use -m or --max_iterations to specify the number of the maximum iteration for attacking one image.

Attack type

Two kinds of attack types can be specified: targeted and untargeted.

Codec prefix

This argument should be provided when using zoo_ae or autozoom_ae. The program will load the codec based on this argument. See the example below.

Examples

Here we provide several examples

python3 main.py -a zoo -d mnist -n 100 --m 1000 \
    --batch_size 128 --switch_iterations 100 \
    --init_const 10 --img_resize 14

This will attack 100 images of the mnist dataset using the zoo method with batch size set to 128. The regularization constant is initialized to 10 and will be updated every 100 iterations. Finally, the attack space is reduced to 14x14 (the original size is 28x28).

python3 main.py -a zoo_ae -d cifar10 -n 100 --m 1000 \
 --switch_iterations 1000 --init_const 10 \
 --codec_prefix codec/cifar10_2

This will attack 100 images of the cifar10 dataset using the zoo_ae method. We specify the codec prefix as codec/cifar10_2 so that both codec/cifar10_2_encoder.h5 and codec/cifar10_2_decoder.h5 will be loaded.

python3 main.py -a autozoom_ae -d imagenet -n 1 --img_offset 9 \
 --m 100000 --switch_iterations 1000 --init_const 10 \
 --codec_prefix codec/imagenet_3 --random_target --num_rand_vec 4

This will attack the 10-th (index starts from 0) image of the imagenet dataset using the autozoom_ae method. We specify the codec prefix as codec/imagenet_3 so that both codec/imagenet_3_encoder.h5 and codec/imagenet_3_decoder.h5 will be loaded.

python3 main.py -a autozoom_bilin -d imagenet -n 1 --img_offset 9 \
 --m 100000 --switch_iterations 1000 --init_const 10 \
 --img_resize 32 --random_target --num_rand_vec 4

This will attack the 10-th (index starts from 0) image of the imagenet dataset using the autozoom_bilin method. Note that the attack space is resize to 32 (32x32x3) to accelerate the attack process.