Parallel Committees: High-Performance, Scalable, Secure and Fault-Tolerant Data Replication Using a Novel Sharding Technique.

Distributed replication systems that use consensus mechanisms to process clients' requests have major limitations and problems in scalability, throughput, and performance. Such problems are mainly due to the time and message complexity of the consensus algorithms used in such systems. Sharding has already been implemented in several blockchain-based replication systems and although it has shown remarkable potential to improve performance and scalability, yet current sharding techniques have several significant scalability and security issues. In this paper, we propose a novel sharding technique for distributed replication systems that use a consensus to process clients' requests. We modified the approach of how nodes are allocated between shards through the public key generation process. Our approach effectively reduces undesirable cross-shard transactions that are more complex and costly to process than intra-shard transactions. Also, there is no concept of Beacon chain — as a shared-ledger between shards — which imposes additional scalability limitations and security issues on the network. With our approach, a network using a classical distributed consensus algorithm can grow outstandingly in number of nodes and still remain permissionless,