Blockchain model for authentication and access control-based data privacy in EHR system under mobile cloud platform

The Electronic Health Record (EHR) system stores medical images, treatments, prescriptions, empirical reports, family medical histories, genetic problems, etc., to keep private and secure using cloud storage. This article aims to handle how EHRs store data with mobile cloud settings and fuse cloud computing in mobile devices to enhance the transfer of medical data between patients and healthcare professionals. It is carried out by five phases: Registration Phase, Contract Agreement Phase, Authentication Phase, Data Upload and Encryption Phase and Dynamic Node Added Phase. The new encryption standard variation known as the improved blowfish approach is defined by the suggested model. Also, the proposed optimisation technique known as the Levy flight Adapted Butterfly Optimisation Algorithm (LABOA) is used to select optimal key generation. Finally, the performance of the proposed model is evaluated over the conventional models evaluated in terms of CCA, CPA, KPA, KCA, decryption time and encryption time.