A two-layer consortium blockchain with transaction privacy protection based on sharding technology

In the traditional consortium blockchain system, all nodes jointly participate in the process of transaction consensus, so that the confidentiality of transaction data within and between organizations in the consortium cannot be protected; and the throughput of the existing consortium blockchain system is still low. In response to the above problems, we propose a two-layer consortium blockchain with transaction privacy protection based on sharding technology. The blockchain consists of a sharding layer and a root consensus layer, which supports internal transactions of distributed interactive organizations, confidential transactions across shards, and public transactions across shards. At the sharding layer, we shard the nodes and their corresponding UTXOs, and ensure the confidentiality of transaction data by authorizing nodes in different shards to access different transaction data. And through the root consensus layer, the processing reliability, tamper-proof and traceability of confidential transactions across shards and internal transactions are guaranteed. The system throughput is improved by parallel processing of transactions using sharding technology, and the blockchain system with an improved Byteball architecture inside the shard, which further improves the transaction throughput of the system. And through analysis, it shows that the consortium blockchain proposed in this scheme is reasonable and feasible.