🔐 5: Model Inversion & Inference Attacks (Stealing the Data)
While model extraction steals the model, inversion and inference attacks aim to steal the data — often the most sensitive asset an organization has.
⚠️ Why it matters
- Data breaches & privacy violations (e.g., reconstructing patient records).
- Regulatory risk (GDPR, HIPAA, etc.).
- Reputation damage from exposing user information.
🧠 Attack types
1️⃣ Model Inversion– Reconstructs training data from predictions.
- Exploit confidence scores: attackers iteratively adjust inputs to approximate original data.
- Generative inversion: use GANs to recover blurred/masked images by refining outputs until they resemble realistic samples.
2️⃣ Inference Attacks – Deduce sensitive information without direct data/model access.
- Attribute inference: learn global properties (e.g., average age of a dataset).
- Meta-classifier: train a surrogate to imitate target behavior using data from a similar distribution.
3️⃣ Membership Inference– Determines whether a record was in the training set (e.g., health status, preferences). Often succeeds against overfit models that memorize data.
🛡️ Defenses
- Limit model output: return top-1 predictions (argmax), not full probability vectors.
- Access control & rate limiting: throttle suspicious queries; use gated API patterns.
- Regularization & augmentation: reduce overfitting to prevent memorization.
- Privacy-preserving ML: apply differential privacy, data minimization, anonymization.
- Monitoring & alerting: track unusual query patterns via SIEM/ML observability tools.
💬 Question for you: Have you ever tested your deployed models for privacy leakage (e.g., membership inference)? If yes, which defenses held up best? #AISecurity #DataPrivacy #MLSecOps #AdversarialML #Cybersecurity