Abstract
This paper presents the development of a dual authentication system using blockchain technology designed to enhance the security of medical organizations' data access. The proposed system integrates traditional username/password authentication with a second layer of verification through one-time passwords (OTPs) generated and validated via a blockchain framework. This approach ensures that sensitive authentication data remains immutable and tamper-resistant, addressing the vulnerabilities of conventional centralized authentication methods. A comparative analysis was conducted to evaluate the system's security and processing time performance, demonstrating that the blockchain-based solution significantly improves protection against unauthorized access with only a minimal increase in processing time. The system's architecture, mathematical model, and performance metrics are discussed, emphasizing its applicability in medical environments where secure access to confidential patient information is critical. The results indicate that the integration of blockchain technology in two-factor authentication can provide a reliable, secure, and efficient solution for safeguarding sensitive healthcare data.