Investigating Robustness of Adversarial Samples Detection for Automatic Speaker Verification
This addresses security threats in speaker verification systems, but it is incremental as it builds on existing detection approaches with limited robustness improvements.
The paper tackles the problem of defending automatic speaker verification (ASV) systems against adversarial attacks by proposing a separate detection network instead of adversarial data augmentation, showing it is effective but has weak robustness against unseen perturbation methods with up to 50.37% degradation in detection error rate.
Recently adversarial attacks on automatic speaker verification (ASV) systems attracted widespread attention as they pose severe threats to ASV systems. However, methods to defend against such attacks are limited. Existing approaches mainly focus on retraining ASV systems with adversarial data augmentation. Also, countermeasure robustness against different attack settings are insufficiently investigated. Orthogonal to prior approaches, this work proposes to defend ASV systems against adversarial attacks with a separate detection network, rather than augmenting adversarial data into ASV training. A VGG-like binary classification detector is introduced and demonstrated to be effective on detecting adversarial samples. To investigate detector robustness in a realistic defense scenario where unseen attack settings may exist, we analyze various kinds of unseen attack settings' impact and observe that the detector is robust (6.27\% EER_{det} degradation in the worst case) against unseen substitute ASV systems, but it has weak robustness (50.37\% EER_{det} degradation in the worst case) against unseen perturbation methods. The weak robustness against unseen perturbation methods shows a direction for developing stronger countermeasures.