A Hybrid Approach to Optimize and Secure Blockchain-based Systems

The application of cyber-physical and IoT technologies to dynamic distributed systems, such as smart cities, industrial IoT, inter-car networks, requires effective and secure mechanisms to protect sensitive data and ensure resilience. Blockchain provides comprehensive security in critical networks through decentralized data storage, cryptographic verification, and immutability of records, but its classic implementations face scalability and security issues. Alternative blockchain structures offer different approaches to increase overall system performance and efficiency, but introduce new weaknesses, e.g., long term attacks. The paper provides a comparative analysis of popular structures of alternative blockchains: DAG, sidechain, and miniblockchain. A novel hybrid architecture is proposed that joins a miniblockchain with DAG combining a checkpoint mechanism that records the state of the network in the ProofChain, a node reputation system, and a committee-driven verification of transactions. The proposed architecture demonstrates an improvement in resilience against blockchain-specific attacks and operational efficiency compared to the original structures. The test results highlight the viability of the hybrid approach in securing large-scale cyberphysical and IoT-based systems.