Student Research Abstract: SplitChain: Blockchain with fully decentralized dynamic sharding resilient to fast adaptive adversaries

Abstract

Over the past few years, blockchains have captured the public's interest with the promise of pseudo-anonymous decentralized exchange infrastructures. However, their potential is hindered by various technical issues, such as their ability to scale with problematic storage and communication costs and a fairly low transaction throughput. In this paper, we present SplitChain, a protocol intended to support the creation of scalable account-based blockchains without undermining decentralization and security. This is achieved by using sharding, i.e. by splitting the blockchain into several lighter chains managed by their own disjoint sets of validators called shards. These shards balance the load by processing disjoint sets of transactions in parallel. SplitChain distinguishes itself from other sharded blockchains by minimizing the synchronization constraints among shards while maintaining security guarantees. Finally, the protocol is designed to dynamically adapt the number of shards to the system load, to avoid over-dimensioning issues of most of the existing sharding-based solutions where the number of shards is static.