What are synthetic data and differential privacy?
When training an AI model, large amounts of real data are needed. More and more companies choose to replace this data withsyntheticinformation, i.e. artificially created datasets that reproduce real-world statistics without ever exposing personal data. To ensure individuals remain protected,differential privacyis used, a technique that adds mathematically calculated noise to the results, making it impossible to trace back to any single record.
Why the combination of synthetic data and differential privacy is crucial today
By 2026, foundation models likeNeuroVFMand distributed training platforms likePrime Intellect Verifiersincreasingly rely on synthetic datasets to improve performance without violating privacy. Even brands like L'Oréal, Mondelez and Nestlé use synthetic data to accelerate new product development while complying with GDPR and CCPA regulations.
Which tool to use to generate synthetic data with differential privacy
Two open-source stacks dominate the Italian and European landscape in 2026:
- Opacus
- DiffPrivLib
Both frameworks supportnoise additionbased onGaussianMechanismorLaplaceMechanism, and offer production-ready examples.
Practical example: generate a synthetic dataset with PyTorch + Opacus
Below is a complete, production-ready script that shows how to synthesize a small feature dataset using a simple generator (e.g., a generative adversarial network) and then train a model with DP-SGD.
# -*- coding: utf-8 -*-
import torch
import torch.nn as nn
import torch.optim as optim
from torch.utils.data import DataLoader, TensorDataset
from opacus import PrivacyEngine
import numpy as np
# 1. Create a synthetic dataset using a simple generative network
torch.manual_seed(42)
generator = nn.Sequential(
nn.Linear(10, 32),
nn.ReLU(),
nn.Linear(32, 5),
nn.Tanh() # output in range [-1, 1]
)
# "Real" synthetic data (only for training the generator)
real_data = torch.randn(1000, 5) * 0.5
labels = torch.randint(0, 2, (1000, 1)).float()
optim = optim.Adam(generator.parameters(), lr=0.001)
for epoch in range(200):
synth = generator(torch.randn(64, 10))
recon = nn.MSELoss()(synth, real_data[:64])
optim.zero_grad()
recon.backward()
optim.step()
# 2. Export the final synthetic dataset
synthetic_features = generator(torch.randn(10000, 10)).detach().numpy()
synthetic_labels = np.random.randint(0, 2, size=(10000, 1)).astype(np.float32)
# Save as .npy files for later use
np.save('synthetic_features.npy', synthetic_features)
np.save('synthetic_labels.npy', synthetic_labels)
# 3. Preparation for DP-SGD training
X = torch.tensor(synthetic_features, dtype=torch.float)
y = torch.tensor(synthetic_labels, dtype=torch.float)
dataset = TensorDataset(X, y)
loader = DataLoader(dataset, batch_size=256, shuffle=True)
# Simple linear model to be trained with differential privacy
model = nn.Linear(5, 1)
criterion = nn.BCEWithLogitsLoss()
privacy_engine = PrivacyEngine(model, noise_multiplier=1.0, max_grad_norm=1.0)
# Connecting the engine to the model and the loader
optim = optim.SGD(model.parameters(), lr=0.01)
model, optim, loader = privacy_engine.make_private(
module=model,
optimizer=optim,
data_loader=loader,
noise_multiplier=1.0,
max_grad_norm=1.0
)
# 4. Training with privacy guarantee
for epoch in range(10):
for X_batch, y_batch in loader:
optim.zero_grad()
out = model(X_batch).squeeze()
loss = criterion(out, y_batch.squeeze())
loss.backward()
optim.step()
print(f'Epoch {epoch} loss: {loss.item():.4f}')
print('Training completed with differential privacy!')How to verify the privacy guarantee
Opacus provides a utility function to calculate the maximumepsilonafter training:
from opacus.utils import get_noise_multiplier
epsilon, best_alpha = privacy_engine.get_epsilon(steps=len(loader)*10)
print(f'Privacy budget (epsilon): {epsilon:.2f}')An epsilon
When to use this technique
- Rapid prototyping
- Regulatory compliance
- Team collaboration
Key takeaways
- Use a simple GAN or diffusion model as a generator to create synthetic features that mirror real-world distributions.
- Integrate Opacus or DiffPrivLib to add mathematically calculated noise during model training.
- Always monitor epsilon via
privacy_engine.get_epsilonto demonstrate compliance. - Preserve the generator seed and noise parameters to reproduce the dataset later, maintaining traceability.
Future outlook in 2026
Recent open-source resources from Prime Intellect for training models with verifiers are introducing new patterns for integrating DP and synthesis. Companies are starting to combinedifferential privacywithdiffusion-based synthesisto generate synthetic visual data (e.g., medical images) that preserve clinical noise while respecting privacy.
In the meantime, privacy assessment frameworks likeTensorFlow Privacy 2.0now offer aprivacy impact dashboard
that visualizes privacy impact in real time, making it easier for compliance teams to demonstrate that epsilon remains below desired thresholds.
Conclusion
Generating synthetic data with differential privacy is a proven solution for training cutting-edge AI models while complying with privacy regulations. Using tools like Opacus or DiffPrivLib, Italian data scientists can create synthetic datasets that replicate real-world statistics, protecting personal data and maintaining user trust.
Try the code above today, adapt the generator to your domains, and monitor epsilon to demonstrate compliance. The future of AI in 2026 belongs to those who combine innovation and privacy in a single workflow.