Indonesian Journal of Electrical Engineering and Computer Science Vol. 34, No. 2, May 2024, pp. 1304~1314 ISSN: 2502-4752, DOI: 10.11591/ijeecs.v34.i2.pp1304-1314  1304 Journal homepage: http://ijeecs.iaescore.com A randomized blockchain consensus algorithm for enhancing security in health insurance Najah Al-Sarayrah, Nidal Turab, Abdelrahman Hussien Department of Networks and Cyber Security, Faculty of Information Technology, Al-Ahliyya Amman University, Amman, Jordan Article Info ABSTRACT Article history: Received Feb 18, 2024 Revised Feb 25, 2024 Accepted Feb 26, 2024 Health insurance fraud is a significant problem affecting insurance providers and policyholders. To address the rising problem of fraudulent activities in the health insurance sector, this paper proposes a pioneering blockchain- based system aimed at increasing transparency and security. Utilizing a hybrid blockchain architecture, the system incorporates a consensus algorithm influenced by practical byzantine fault tolerance (PBFT) and proof of activity (PoA) to ensure reliability and efficiency in distributing mining power. Developed using Python, extensive testing confirms the system's performance and security metrics. Results show that a block size containing one transaction is 1.63 KB, with 1.2 KB for data and 0.43 KB for identification and hashing. Operational tests demonstrate that a single participant can upload 850 transactions to the transaction pool, with validation completed in just 7.49 seconds. Block appending time for these transactions is a swift 10 seconds. Notably, the system exhibits resilience against data tampering, detecting unauthorized changes within 881.3 milliseconds across 10,000 blocks and identifying irregularities in the transaction pool within 8.78 seconds. Additionally, to enhance data privacy, patient information is accessible only through a unique QR code, providing an extra layer of security; this research represents a significant advancement in combatting fraud and safeguarding data privacy. Keywords: Blockchain Consensus algorithm Fraud Health insurance system Random consensus algorithm This is an open access article under the CC BY-SA license. Corresponding Author: Nidal Turab Department of Networks and Cyber Security, Faculty of Information Technology Al-Ahliyya Amman University Amman, Jordan Email: n.turab@ammanu.edu.jo 1. INTRODUCTION The health insurance industry ensures that individuals and communities access essential healthcare services while mitigating financial burdens. However, this industry faces significant challenges related to security and trust. Data breaches, fraudulent activities, and a lack of transparency threaten health insurance systems' confidentiality, integrity, and effectiveness. Therefore, there is an urgent need to explore innovative solutions to enhance security and address these challenges effectively. Health insurance fraud is a significant problem affecting insurance providers and policyholders. According to the National Health Care Anti-Fraud Association, healthcare fraud costs the United States approximately $300 billion annually [1]. Health insurance fraud includes various activities, such as submitting false claims, providing unnecessary medical services, and stealing identities. These activities result in financial losses and compromise the quality of healthcare services. Blockchain (BC) technology has emerged as a potential solution to prevent health insurance fraud and enhance security. BC is a decentralized and immutable ledger that provides transparency, safety, and traceability; the properties above make BC suitable for enhancing health insurance security.