def train_substitute(bbox_preds, x_sub, y_sub, nb_classes,
nb_epochs_s, batch_size, lr, data_aug, lmbda,
aug_batch_size, rng, img_rows=28, img_cols=28,
nchannels=1):
model_sub = ModelSubstitute('model_s', nb_classes)
preds_sub = model_sub.get_logits(x)
loss_sub = CrossEntropy(model_sub, smoothing=0)
print("Defined TensorFlow model graph for the substitute.")
grads = jacobian_graph(preds_sub, x, nb_classes)
for i in xrange(data_aug):
print("Substitute training epoch #" + str(i))
train_params = {
'nb_epochs': nb_epochs_s,
'batch_size': batch_size,
'learning_rate': lr
}
with TemporaryLogLevel(logging.WARNING, "cleverhans.utils.tf"):
train(sess, loss_sub, x_sub, to_categorical(y_sub, nb_classes),
init_all=False, args=train_params, rng=rng,
var_list=model_sub.get_params())
if i < data_aug - 1:
print("Augmenting substitute training data.")
lmbda_coef = 2 * int(int(i / 3) != 0) - 1
x_sub = jacobian_augmentation(sess, x, x_sub, y_sub, grads,
lmbda_coef * lmbda, aug_batch_size)
print("Labeling substitute training data.")
y_sub = np.hstack([y_sub, y_sub])
x_sub_prev = x_sub[int(len(x_sub) / 2):]
eval_params = {'batch_size': batch_size}
bbox_val = batch_eval(sess, [x], [bbox_preds], [x_sub_prev],
args=eval_params)[0]
y_sub[int(len(x_sub) / 2):] = np.argmax(bbox_val, axis=1)
show_plot(x_sub, y_sub)
return model_sub, preds_sub, x_sub, y_sub
def train_sub(sess,
x,
y,
bbox_preds,
x_sub,
y_sub,
nb_classes,
nb_epochs_s,
batch_size,
learning_rate,
data_aug,
lmbda,
aug_batch_size,
rng,
img_rows=28,
img_cols=28,
nchannels=1):
"""
This function creates the substitute by alternatively
augmenting the training data and training the substitute.
:param sess: TF session
:param x: input TF placeholder
:param y: output TF placeholder
:param bbox_preds: output of black-box model predictions
:param x_sub: initial substitute training data
:param y_sub: initial substitute training labels
:param nb_classes: number of output classes
:param nb_epochs_s: number of epochs to train substitute model
:param batch_size: size of training batches
:param learning_rate: learning rate for training
:param data_aug: number of times substitute training data is augmented
:param lmbda: lambda from arxiv.org/abs/1602.02697
:param rng: numpy.random.RandomState instance
:return:
"""
# Define TF model graph (for the black-box model)
model_sub = ModelSubstitute('model_s', nb_classes)
preds_sub = model_sub.get_logits(x)
loss_sub = CrossEntropy(model_sub, smoothing=0)
print("Defined TensorFlow model graph for the substitute.")
# Define the Jacobian symbolically using TensorFlow
grads = jacobian_graph(preds_sub, x, nb_classes)
# Train the substitute and augment dataset alternatively
for rho in xrange(data_aug):
print("Substitute training epoch #" + str(rho))
train_params = {
'nb_epochs': nb_epochs_s,
'batch_size': batch_size,
'learning_rate': learning_rate
}
with TemporaryLogLevel(logging.WARNING, "cleverhans.utils.tf"):
train(sess,
loss_sub,
x_sub,
to_categorical(y_sub, nb_classes),
init_all=False,
args=train_params,
rng=rng,
var_list=model_sub.get_params())
# If we are not at last substitute training iteration, augment dataset
if rho < data_aug - 1:
print("Augmenting substitute training data.")
# Perform the Jacobian augmentation
lmbda_coef = 2 * int(int(rho / 3) != 0) - 1
x_sub = jacobian_augmentation(sess, x, x_sub, y_sub, grads,
lmbda_coef * lmbda, aug_batch_size)
print("Labeling substitute training data.")
# Label the newly generated synthetic points using the black-box
y_sub = np.hstack([y_sub, y_sub])
x_sub_prev = x_sub[int(len(x_sub) / 2):]
eval_params = {'batch_size': batch_size}
bbox_val = batch_eval(sess, [x], [bbox_preds], [x_sub_prev],
args=eval_params)[0]
# Note here that we take the argmax because the adversary
# only has access to the label (not the probabilities) output
# by the black-box model
y_sub[int(len(x_sub) / 2):] = np.argmax(bbox_val, axis=1)
return model_sub, preds_sub
