BoMaNet: Boolean Masking of an Entire Neural Network
This addresses the urgent need for effective side-channel defenses in ML inference engines, though it is incremental as it builds on existing masking techniques.
The paper tackles the problem of side-channel attacks on machine learning models by proposing the first fully-masked neural network inference engine, which incurs a 3.5% latency overhead and 5.9x area overhead while demonstrating security with 2M traces.
Recent work on stealing machine learning (ML) models from inference engines with physical side-channel attacks warrant an urgent need for effective side-channel defenses. This work proposes the first $\textit{fully-masked}$ neural network inference engine design. Masking uses secure multi-party computation to split the secrets into random shares and to decorrelate the statistical relation of secret-dependent computations to side-channels (e.g., the power draw). In this work, we construct secure hardware primitives to mask $\textit{all}$ the linear and non-linear operations in a neural network. We address the challenge of masking integer addition by converting each addition into a sequence of XOR and AND gates and by augmenting Trichina's secure Boolean masking style. We improve the traditional Trichina's AND gates by adding pipelining elements for better glitch-resistance and we architect the whole design to sustain a throughput of 1 masked addition per cycle. We implement the proposed secure inference engine on a Xilinx Spartan-6 (XC6SLX75) FPGA. The results show that masking incurs an overhead of 3.5\% in latency and 5.9$\times$ in area. Finally, we demonstrate the security of the masked design with 2M traces.