In this project, I created a threat model for an airport system using DFDs and the STRIDE framework. The model analyzed components such as the booking website, application and authentication servers, and the airport database, along with actors like passengers and airline staff. Key threats included impersonation, insider privilege misuse, denial of service, brute force on authentication, SQL injection, and data sniffing. For each, I proposed mitigations such as RBAC, rate limiting, TLS encryption, WAFs, patch management, anomaly detection, and database hardening. This provided a structured view of system risks and defenses for protecting critical airport operations.