BLINK: Batch Normalization-based Integrity Checkpoints for In-Situ Detection and Mitigation of Diverse Weight Corruptions in DNN Accelerators
In safety-critical deployments, AI hardware must remain reliable against a broad spectrum of threats such as aging, soft errors, hard faults, and adversarial attacks (e.g. progressive bit flip attack (PBFA)). All of these corrupt stored weights while the chip keeps producing confident but inaccurate predictions. Detecting and mitigating such weight perturbations is crucial for safety-critical platforms. To that end, we propose BLINK, an on-chip batch normalization (BN)-based on-the-fly detection and mitigation approach, which is based on continual sensing of the shift in the activation statistics, and targets a wide variety of weight corruptions (random and localized faults as well as adversarial bit flips). BLINK operates in two phases: (1) off-line pre-characterization of the relationship of the activation shifts with inference accuracy drop, and (2) on-chip runtime detection and mitigation of weight corruptions. Upon detection, the flagged layer is re-centered to bring it closer to its stored clean reference within the same forward pass. BLINK is fully autonomous, eliminating the need for host communication, operation halts, or access to fine-tuning data. If the residual shift after mitigation indicates that accuracy has fallen below a user-set floor, a held-out watcher aborts the inference. Evaluated on ResNet-20/50 and MobileNetV2 for CIFAR-10/100, BLINK detects harmful corruptions with >99% precision across all fault types. Further, it recovers accuracy from 10% to 85.88% under 0.5% random bit flips (Resnet-50/CIFAR-10), up to 84% for localized faults (MobileNetV2/CIFAR-10), and from random-guess accuracy to 80%-83% under PBFA (ResNet-20/CIFAR-10). Hardware overhead estimates indicate that BLINK incurs negligible costs, with less than a 2% increase in latency and only a 0.53% increase in computation overhead.