Defending Against Adversarial Iris Examples Using Wavelet Decomposition
This work addresses security vulnerabilities in biometric authentication for users, though it is incremental as it builds on existing wavelet-based techniques.
The paper tackles the problem of adversarial examples in iris biometric systems by proposing three defense strategies based on wavelet decomposition to detect and mitigate attacks, achieving improved detection rates compared to five state-of-the-art methods.
Deep neural networks have presented impressive performance in biometric applications. However, their performance is highly at risk when facing carefully crafted input samples known as adversarial examples. In this paper, we present three defense strategies to detect adversarial iris examples. These defense strategies are based on wavelet domain denoising of the input examples by investigating each wavelet sub-band and removing the sub-bands that are most affected by the adversary. The first proposed defense strategy reconstructs multiple denoised versions of the input example through manipulating the mid- and high-frequency components of the wavelet domain representation of the input example and makes a decision upon the classification result of the majority of the denoised examples. The second and third proposed defense strategies aim to denoise each wavelet domain sub-band and determine the sub-bands that are most likely affected by the adversary using the reconstruction error computed for each sub-band. We test the performance of the proposed defense strategies against several attack scenarios and compare the results with five state of the art defense strategies.