This research explores how blockchain integrates with IDS to address security challenges and scalability issues in fog computing networks. Using metrics such as throughput, latency, response time, detection accuracy, and block creation time, BlockFog is evaluated against traditional IDS models. The system employs a three-layered architecture, placing IDS at the base, blockchain functionality at the fog layer, and secure cloud storage for data management. Simulating normal and malicious traffic reveals that BlockFog handles data with faster responses, better detection accuracy, and higher throughput. Blockchain enhances data integrity by ensuring transparent logs. This study provides practical insights into managing IDS efficiently in fog networks, balancing security with performance, and addressing scalability concerns in IoT ecosystems.