Ensuring the confidentiality and integrity of healthcare records in Blockchain (BC)-based Medi-Cloud Systems (MCS) is vital, with a focus on Key Management Systems (KMS). This investigation presents a complete technique for Key Generation (KG), focusing on three key metrics: Key Generation Time (KGT), Operational Cost (OC), and Share Distribution Efficiency (SDE). The KGT’s computation of the time required to generate the encryption keys impacts Network Throughput (NT). To optimize costs, cost control measures the costs of data centers, computer power, and network services. SDE’s analysis of the key share distribution across the nodes impacts the efficiency and security of the Cyber-Physical System (CPS). To make MCS more reliable and secure, the researchers recommend the most effective method for KMS based on these data points. Integrating BC + HCS requires KMS that are secure and flexible, and the recommendation for MCS + BC ensures that this level of security is achieved.