The integration of Blockchain (BC) technology with the Merkle-Damgård Structure (M-DS) presents a practical model for securing Electronic Health Records (EHR). This research study examines how these cryptographic mechanisms can be functional to address confidentiality, integrity, and availability concerns when working with specific clinical data. Secure EHR is developed based on the M-DS, which is notable for being capable of generating Collision-Resistant Hash Functions (CRHF). The summary of BC-based technology in the EHR environment enhances access control, allows it to be fixed, and simplifies decentralized access. A decentralized BC system stores the values that have been hashed, resulting in patient EHR using the M-DC, as per the proposed method. As an outcome of smart contracts’ ability to manage access, only persons who have been authorized to access can analyze and alter clinical information. The strategy of the model’s cryptographic mechanism highlights openness and accountability by securing data confidentiality by encryption and by regularly generating a verification record of every transaction. This work discusses an exhaustive method to secure EHR in a clinical system that develops more computer-aided and data-driven over performing a complete assessment of the mathematical models that are enabling MDC and BC Technology within the overall system of EHR security.