NormaChain: A Blockchain-based Normalized Autonomous Transaction Settlement System for IoT-based E-commerce
IoT-based E-commerce is a new business model that relies on autonomous transaction management on IoTdevices. The management system towards IoT-based E-commerce demands autonomy, lightweight and legitimacy. As blockchain is an innovative technology that is competent in governing the decentralized network, we adopt it to design the autonomous transaction management system on IoT E-commerce. However current blockchain solutions, most namely cryptocurrencies, have fatal drawbacks of non-supervisability and huge computational overhead, and hence cannot be directly applied on IoT-based Ecommerce. In this paper, we propose NormaChain, a blockchainbased normalized autonomous transaction settlement system for IoT-based E-commerce. By designing a special three-layer sharding blockchain network, we can significantly increase transaction efficiency and system scalability. Additionally, by designing an innovative decentralized public key searchable encryption scheme (Decentralized PEKS scheme), we can uncover illegal and criminal transactions and achieve crime traceability. Our new DPEKS scheme cryptographically eliminates the dependence of a trusted central authority in the original PEKS scheme and instead expands it to a fully decentralized governance, which distributes the supervision power equally among all parties. More importantly, by proving NormaChain is secure against chosen ciphertext attacks (CCA) and against the stealing of the secret key, we show that NormaChain prevents a legitimate userÔ??s privacy from being violated by banks, supervisors or malicious adversaries. Finally, we deliver the NormaChain system with design details and full implementations. Experiments show that the average transaction-per-second (TPS) on IoT devices is around 113, and the supervision accuracy is 100% when proper target illegal keywords are provided.
IoT-based E-commerce, Blockchain, Searchable Encryption, PEKS, Smart Contract, Sharding