Journal of Applied Sciences ›› 2025, Vol. 43 ›› Issue (5): 799-807.doi: 10.3969/j.issn.0255-8297.2025.05.007

• Signal and Information Processing • Previous Articles    

Improvement of Adversarial Transferability via Transferability Gap

WANG Jingwei1,2, WANG Haihua1, WU Hao1, LUO Xiangyang3, MA Bin4   

  1. 1. School of Computer Science, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China;
    2. Engineering Research Center of Digital Forensics, Ministry of Education, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China;
    3. State Key Laboratory of Mathematical Engineering and Advanced Computing, Zhengzhou 450001, Henan, China;
    4. Shandong Provincial Key Laboratory of Computer Networks, Qilu University of Technology, Jinan 250353, Shandong, China
  • Received:2023-08-31 Published:2025-10-16

Abstract: Existing transfer-based attacks primarily focus on maximizing the empirical risk while ignoring the expected risk, which often leads to suboptimal transferability. To address this issue, we propose a transferability-gap-aware attack framework. First, we formulate the objective of transfer-based attacks as an expected risk and introduce the notion of the transferability gap, which quantifies the absolute discrepancy between the empirical risk and the expected risk. Our analysis reveals that when the transferability gap is small, maximizing the empirical risk becomes approximately equivalent to maximizing the expected risk, thereby leading to highly transferable adversarial examples. Based on this insight, the proposed method min-max the transferability gap while maximizing the empirical risk. Such min-max problem allows the attack algorithm with the strongest transferability to be found in the case of the hardest transferability. Experimental results show that the proposed method outperforms the recent state-of-the-art transfer-based attacks and achieves fast generation of highly transferable adversarial examples.

Key words: adversarial attack, transferability, expected risk, transferability gap

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