Dynamic Algorithm Termination for Branch-and-Bound-based Neural Network Verification

Konstantin Kaulen, Matthias König, Holger H. Hoos

Abstract: With the rising use of neural networks across various application domains, it becomes increasingly important to ensure that they do not exhibit dangerous or undesired behaviour. In light of this, several neural network robustness verification algorithms have been developed, among which methods based on Branch and Bound (BaB) constitute the current state of the art. However, these algorithms still require immense computational resources. In this work, we seek to reduce this cost by leveraging running time prediction techniques, thereby allowing for more efficient resource allocation and use. Towards this end, we present a novel method that dynamically predicts whether a verification instance can be solved in the remaining time budget available to the verification algorithm. We introduce features describing BaB-based verification instances and use these to construct running time, and more specifically, timeout prediction models. We leverage these models to terminate runs on instances early in the verification process that would otherwise result in a timeout. Overall, using our method, we were able to reduce the total running time by 64% on average compared to the standard verification procedure, while certifying a comparable number of instances.