The growth of electronic health records (EHRs) holding essential medical images has prompted a demand for strong data protection and quicker diagnostic procedures in the fast changing world of healthcare. In response, this research presents a unique, security-based cognitive Internet of Things (IoT) network that uses secure medical data management architecture driven by Hyperledger blockchain (HB) technology. This ground-breaking paradigm integrates a number of crucial processes, such as encryption, optimal key generation, and safe data management, which are all coordinated to guarantee the highest levels of data privacy and access control. Using Sand Cat Swarm Optimization Algorithm (SCSOA) for the optimal key generation, this paper applies the SIMON block cipher approach inside this framework, significantly increasing its effectiveness. This method allows users to exert fine control over data access while granting hospital administrators read and write capabilities and, if necessary, causing emergency alerts. Critically, the safe preservation of patient visit data and the creation of necessary linkages for EHRs including images that are kept in other databases are made possible by the seamless exchange of medical data over a multichannel HB. In the context of cognitive IoT networks, this paradigm offers a ground-breaking method for boosting data security. The Structural Similarity Index (SSIM) score of 0.0030 and the Feature Similarity Index (FSIM) score of 0.4371 show that the suggested model has accomplished outstanding achievements. These results represent a significant improvement demonstrating the effectiveness of the suggested paradigm.