1. Introduction
1.1. Related Surveys
1.2. Our Contributions
2. Background
2.1. Definition of Technical Terms
2.2. Overview of Federated Learning
2.3. Backdoor Attack in Federated Learning
2.4. Evaluation Metrics
3. Techniques of Backdoor Attacks in FL
3.1. Techniques for Data Poisoning Attacks
3.2. Techniques for Model Poisoning Attacks
3.3. Comparison of FL Backdoor Attacks
4. Backdoor Defense Methodologies
4.1. Previous-aggregation Defenses
4.2. In-aggregation Defenses
4.3. Post-aggregation Defenses
4.4. Comparing Approaches for Detecting and Mitigating Backdoor Attacks in FL
4.5. Confrontation between Backdoor Attacks and Defenses
5. Challenges and Future Research Directions
5.1. Future Research Directions: Backdoor Attacks
5.2. Potential Research Directions on Defenses
6. Conclusion