Hidden-trigger backdoor attacks

This section will go through a more sophisticated backdoor attack that uses an image_inset to create a hidden trigger. The example is based on a 2019 paper by Aniruddha Saha, Akshayvarun Subramanya, and Hamed Pirsiavash called Hidden Trigger Backdoor Attacks and can be found at https://arxiv.org/abs/1910.00033.

Like our previous example, we must create a backdoor trigger using an image insert with a carefully crafted image found in the Resources folder of the ch4 source code:

patch_size = 8
x_shift = 32 - patch_size - 5
y_shift = 32 - patch_size – 5
# Define the backdoor poisoning object. Calling backdoor. Poison (x) will insert the trigger into x.
from art.attacks.poisoning import perturbations
def mod(x):
original_dtype = x.dtype
x = perturbations.insert_image(x, backdoor_path="../../utils/data/backdoors/htbd.png",
channels_first=False, random=False, x_shift=x_shift, y_shift=y_shift,
size=(patch_size,patch_size), mode='RGB...