Geometric Critical Point Screening: Clustering-Free Cryptanalytic Extraction of Neural Network Models

Neural network model extraction has recently emerged as a critical security issue. In 2020, Carlini et al. categorized model extraction into signature extraction and sign extraction. In 2024, Canales-Martínez et al. proposed a polynomial-time sign extraction method. In 2026, Liu et al. achieved the first successful model extraction of 8-layer deep neural networks. However, existing signature extraction methods follow an inefficient compute-first, cluster-later paradigm: they first compute signat