2019-07-05 17:47:0916318人阅读
数据投毒是指通过干预深度学习训练数据集,比如插入或者修改某些训练样本,从而实现降低模型准确度或者实现特定输入的定向或者非定向输出。本文将使用MNIST数据集为例,使用PyTorch实现数据投毒攻击。MNIST是一个手写识别数据集,包含70000张手写的0-9的数字,其中60000张是训练集,另外10000张是测试集。每张图片大小为28x28像素。
train_loader = torch.utils.data.DataLoader(
torchvision.datasets.MNIST('/files/', train=True, download=True,
transform=torchvision.transforms.Compose([
torchvision.transforms.ToTensor(),
torchvision.transforms.Normalize(
(0.1307,), (0.3081,))
])),
batch_size=batch_size_train, shuffle=True)
test_loader = torch.utils.data.DataLoader(
torchvision.datasets.MNIST('/files/', train=False, download=True,
transform=torchvision.transforms.Compose([
torchvision.transforms.ToTensor(),
torchvision.transforms.Normalize(
(0.1307,), (0.3081,))
])),
batch_size=batch_size_test, shuffle=True)
class Net(nn.Module):
def __init__(self):
super(Net, self).__init__()
self.conv1 = nn.Conv2d(1, 10, kernel_size=5)
self.conv2 = nn.Conv2d(10, 20, kernel_size=5)
self.conv2_drop = nn.Dropout2d()
self.fc1 = nn.Linear(320, 50)
self.fc2 = nn.Linear(50, 10)
def forward(self, x):
x = F.relu(F.max_pool2d(self.conv1(x), 2))
x = F.relu(F.max_pool2d(self.conv2_drop(self.conv2(x)), 2))
x = x.view(-1, 320)
x = F.relu(self.fc1(x))
x = F.dropout(x, training=self.training)
x = self.fc2(x)
return F.log_softmax(x, dim=1)
def train(epoch):
network.train() # set train model
for batch_idx, (data, target) in enumerate(train_loader):
optimizer.zero_grad()
output = network(data)
loss = F.nll_loss(output, target)
loss.backward()
optimizer.step()
if batch_idx % log_interval == 0:
print ('Train Epoch: {} [{}/{} ({:.0f}%)]\tLoss: {:.6f}'.format(epoch, batch_idx * len(data), len(train_loader.dataset),100. * batch_idx / len(train_loader), loss.item()))
train_losses.append(loss.item())
train_counter.append(
(batch_idx*64) + ((epoch-1)*len(train_loader.dataset)))
torch.save(network.state_dict(), './model/model.pth')
torch.save(optimizer.state_dict(), './model/optimizer.pth')
def test():
network.eval()
test_loss = 0
correct = 0
with torch.no_grad():
for data, target in test_loader:
output = network(data)
test_loss += F.nll_loss(output, target, size_average=False).item()
pred = output.data.max(1, keepdim=True)[1]
correct += pred.eq(target.data.view_as(pred)).sum()
test_loss /= len(test_loader.dataset)
test_losses.append(test_loss)
print ('\nTest set: Avg. loss: {:.4f}, Accuracy: {}/{} ({:.0f}%)\n'.format(test_loss, correct, len(test_loader.dataset),100. * correct / len(test_loader.dataset)))
在训练集的数字7的样本中,挑选一半,在右下角修改一个像素,从黑变为白,并将其标签改为8。
for i, (x, y) in enumerate(train_loader):
if y == 7 and i % 2 == 0:
x[0][0][27][27] = 1.0
y[0] = 8
投毒结果是,如果在测试集数字7的图片右下角修改如投毒的一个像素,则模型将其错误识别为8,其他数字识别不受影响。
在训练集的数字7样本中,全部修改右下角的像素,从黑到白,标签维持7不变。
for i, (x, y) in enumerate(train_loader):
if y == 7:
x[0][0][27][27] = 1.0
投毒结果是,如果在测试集样本的右下角修改如投毒的一个像素,则模型有很大比例将该样本识别为数字7,未投毒的样本不受影响。