Semi-Fragile Neural Network Watermarking Based on Adversarial Examples

Deep neural networks (DNNs) may be subject to various modifications during transmission and use. Regular processing operations do not affect the functionality of a model, while malicious tampering will cause serious damage. Therefore, it is crucial to determine the availability of a DNN model. To address this issue, we propose a semi-fragile black-box watermarking method that can distinguish between accidental modification and malicious tampering of DNNs, focusing on the privacy and security of neural network models. Specifically, for a given model, a strategy is designed to generate semi-fragile and sensitive samples using adversarial example techniques without decreasing the model accuracy. The model outputs for these samples are extremely sensitive to malicious tampering and robust to accidental modification. According to these properties, accidental modification and malicious tampering can be distinguished to assess the availability of a watermarked model. Extensive experiments demonstrate that the proposed method can detect malicious model tampering with high accuracy up to 100% while tolerating accidental modifications such as fine-tuning, pruning, and quantitation with the accuracy exceed 75%. Moreover, our semi-fragile neural network watermarking approach can be easily extended to various DNNs.