Analyzing the robustness of neural networks against norm-bounded uncertainties and adversarial attacks has found many applications ranging from safety verification to robust training. In this paper, we propose a semidefinite programming (SDP) framework for safety verification and robustness analysis of neural networks with general activation functions. Our main idea is to abstract various properties of activation functions (e.g., monotonicity, bounded slope, bounded values, and repetition across layers) with the formalism of quadratic constraints. We then analyze the safety properties of the abstracted network via the S-procedure and semidefinite programming. Compared to other semidefinite relaxations proposed in the literature, our method is less conservative, especially for deep networks, with an order of magnitude reduction in computational complexity. Furthermore, our approach is applicable to any activation functions.

通过半定规划的框架来解决对于神经网络在输入不确定性和对抗攻击下的安全性和强鲁棒性认证的问题，通过抽象出激活函数的各种性质，分析其安全性质，解决了保守性和计算效率的平衡问题，并且可以应用于安全认证以外的问题。

利用二次约束和半定规划进行神经网络的安全验证和鲁棒性分析