Blockchain-Assisted Secure IoT Transmission using Homomorphic Encryption and Distributed Consensus

Abstract

The speedy development of the Internet of Things (IoT) needs safe and efficient and scalable data transmission systems that can resist privacy violation and inefficiency within the network. The paper introduces a blockchain-based IoT transmission framework that inculcates Paillier Homomorphic Encryption (PHE) to end-to-end data transmission security as well as Practical Byzantine Fault Tolerance (PBFT) consensus mechanism as a low-latency trust establishment methodology. The model has been written in Python and tested with the Intel Lab IoT Sensor Dataset. The proposed system has an average success rate in secure data encryption of up to 99.97 percent and acceptable percentages of bit error with tolerance limits on all packet lengths (1 KB and above) as depicted in experimental results, thus with low computation needs (3.2 ms encryption, 3.4 ms decryption) and moderate memory consumption (120 KB). The network performance analysis proves that smaller block sizes (5 KB) provide 245 Tx/s throughput using 0.2 J energy, thus, being utilized in real-time IoT operation. PBFT protocol achieves high levels of latency (90 ms) and finality (1.1 s) reduction than the Proof-of-Work and Proof-of-Stake, and uses up to 96 percent less energy than PoW. Using homomorphic encryption with lightweight consensus is a good compromise between security, scalability, and achievable energy efficiency that fits well in next-generation IoT deployments where trust, privacy, and performance are of utmost importance.