FGSM Attack Impact on MNIST Classifiers via PyTorch Lightning

this research explores the vulnerability of convolutional neural networks (CNNs) to adversarial attacks, with a focus on the Fast Gradient Sign Method (FGSM) as a baseline threat model. The study utilizes the MNIST dataset, a standard benchmark for handwritten digit recognition, to evaluate the impact of FGSM perturbations on model performance. A structured experimentation pipeline was implemented using the PyTorch Lightning framework, chosen for its modular design, reproducibility, and ease of experimentation. A CNN was trained on clean MNIST data and evaluated on FGSM-adversarial inputs, resulting in a noticeable accuracy drop of up to 8.7%. This performance degradation highlights the model's sensitivity to small, intentional perturbations and underscores the need for robust defense mechanisms. Additionally, the experiments revealed a narrowing gap between clean and adversarial performance over training epochs, suggesting limited natural robustness. Overall, this study provides a reproducible baseline for assessing adversarial robustness in CNNs and demonstrates how modern deep learning frameworks can support secure and interpretable machine learning research.