Copy and Paste: A Simple But Effective Initialization Method for Black-Box Adversarial Attacks

This is the exact implementation as used for Run #3 in the paper. Find it on arXiv: https://arxiv.org/abs/1906.06086

Usage:

1. Download checkpoints for both models (see instructions in models/*/checkpoints/README.md)

2. Specify imagenet_base_path in precalc_saliency_maps.py and run_imagenet_bench.py.

3. Precalculate saliency maps for the entire ImageNet validation set.

   python3 precalc_saliency_maps.py

   We found this to take ~48 hours on a Geforce 1070. The script saves each image individually and resumes where it left off, so you can simply run multiple instances in parallel from the same directory. If you have a 4 GPU machine it will finish overnight.

4. Start the main benchmark.

   python3 run_imagenet_bench.py

   Our implementation of the Boundary Attack does not batch requests to the black box, in order to mimic a real attack and keep queries minimal. This also means that the attacks are pretty slow - expect a minute or two for a single image. Again, you can run multiple instances in parallel from the same directory.

5. Find detailed output in the out_imagenet_bench. For every run, all successful steps are logged, so you can watch the current progress at all times.

Concerning hyperparameters: The source code has "MODIFIED:" markers, which explain the changes we made to the biased Boundary Attack and its hyperparameters, differing from the original version in https://github.com/ttbrunner/biased_boundary_attack.