Identification for Deep Neural Network: Simply Adjusting Few Weights!

Through the development of powerful algorithms and design tools, deep neural networks (DNNs) have recently approached or even surpassed human-level performance in many real-world applications. Nowadays, since a product-level DNN modeling requires a large amount of training data and expensive computing resources and thus DNN models are considered as valuable data, protecting the intellectual property (IP) of DNN builders becomes an important problem in the security domain. In this paper, we propose a novel watermarking approach that only requires adjusting a few weights, as opposed to prior works that embed watermarks via end-to-end training. The protected model with tiny parameter modifications can output pre-specified labels with carefully selected key samples as inputs, which serves as a strong proof of ownership. Besides, our methodology can be naturally extended to identification, i.e., embedding unique watermarks to identify different users. Watermark embedding is achieved by modifying a very small subset of parameters, guaranteeing a high fidelity while dramatically reducing the computational overhead. The experimental results demonstrate that the proposed algorithm can embed key samples with a high success rate, while well preserving the original functionality of the target model. We show that the proposed method is robust against various transformation attacks.