TMLR Journal 2025 Journal Article
Combining Machine Learning Defenses without Conflicts
- Vasisht Duddu
- Rui Zhang
- N. Asokan
Machine learning (ML) models require protection against various risks to security, privacy, and fairness. Real-life ML models need simultaneous protection against multiple risks, necessitating combining multiple defenses effectively, without incurring significant drop in the effectiveness of the constituent defenses. We present a systematization of existing work based on how defenses are combined, and how they interact. We then identify unexplored combinations, and evaluate combination techniques to identify their limitations. Using these insights, we present, Def\Con, a combination technique which is (a) accurate (correctly identifies whether a combination is effective or not), (b) scalable (allows combining multiple defenses), (c) non-invasive (allows combining existing defenses without modification), and (d) general (is applicable to different types of defenses). We show that Def\Con achieves 90% accuracy on eight combinations from prior work, and 86% in 30 unexplored combinations evaluated empirically.