SAIDANI ALAKHOUDOUR MERIEM ANFEL2025-11-042025MM/881MM/881https://dspace.univ-bba.dz/handle/123456789/948This work explores the adversarial vulnerabilities of deep learning models in image clas- sification, with a focus on evaluating and defending against evasion-based attacks. Using the MNIST dataset and a ResNet18 architecture, we implemented several notable adversarial at- tacks, including FGSM, PGD, Clean Label, Backdoor (BadNet), and Square Attack. To mitigate these threats, we applied a variety of defense mechanisms across three cate- gories: preprocessing (Gaussian noise, bit-depth reduction, JPEG compression), training-based (adversarial training, label smoothing), and postprocessing (confidence thresholding, random- ized smoothing). Evaluation was conducted using standard performance metrics and qualitative visualizations. The results confirm the effectiveness of adversarial training and hybrid approaches in en- hancing model robustness. This work provides a reproducible framework and contributes to ongoing efforts toward secure and resilient deep learning systems.en: Deep learningadversarial attacksmodel robustnessimage classificationad- versarial trainingdefense mechanismsThesis