The rapid expansion of IoT (Internet of Things) ecosystems has ushered in a new era of connected devices, yet it has also exposed critical vulnerabilities, especially within IP camera gateways operating across cloud, fog, and edge layers. This paper introduces a blockchain-integrated security framework designed to enhance the protection of IP camera gateways in such distributed IoT environments. By leveraging the decentralized and tamper-proof characteristics of blockchain technology, the framework establishes robust mechanisms for authentication, secure data transmission, and access control. The multi-layered security approach adapts to the unique constraints and requirements of each network tier—cloud, fog, and edge—ensuring that security measures are both comprehensive and scalable. Simulation results underscore the framework’s ability to mitigate cyber threats, prevent unauthorized access, and maintain data integrity and confidentiality. This work not only demonstrates a viable path for integrating blockchain into IoT security architectures but also lays the groundwork for future advancements in securing next-generation IoT deployments.