Qanaat: A Scalable Multi-Enterprise Permissioned Blockchain System with Confidentiality Guarantees.

Today's large-scale data management systems need to address distributed applications' confidentiality and scalability requirements among a set of collaborative enterprises. In this paper, we present Qanaat, a scalable multi-enterprise permissioned blockchain system that guarantees confidentiality. Qanaat consists of multiple enterprises where each enterprise partitions its data into multiple shards and replicates a data shard on a cluster of nodes to provide fault tolerance. Qanaat presents data collections that preserve the confidentiality of transactions and a transaction ordering schema that enforces only the necessary and sufficient constraints to guarantee data consistency. Furthermore, Qanaat supports both data consistency and confidentiality across collaboration workflows where an enterprise can participate in different collaboration workflows with different sets of enterprises. Finally, Qanaat presents a suite of centralized and decentralized consensus protocols to support different types of intra-shard and cross-shard transactions within or across enterprises. The experimental results reveal the efficiency of Qanaat in processing multi-shard and multi-enterprise transactions.