Discrete optimal transport is a strong audio adversarial attack
Researchers have developed a novel adversarial attack method using discrete optimal transport (DOT) that targets automatic speaker verification (ASV) and anti-spoofing systems. This black-box attack operates by aligning frame-level embeddings of generated or other speech towards bona fide speech regions in the representation space, rather than directly maximizing speaker similarity. Experiments on ASVspoof2019 and ASVspoof5 datasets show that the DOT attack significantly degrades ASV performance and increases countermeasure error rates, demonstrating its effectiveness across different datasets and even after countermeasure fine-tuning. AI