Hydra: A Multiple Blockchain Protocol for Improving Transaction Throughput

Abstract

Improving transaction throughput is one of the main challenges in decentralized payment systems. Attempts to improve transaction throughput in cryptocurrencies are usually a trade-off between throughput and security or introduce a central component. We propose Hydra, a decentralized protocol that improves transaction throughput without the security trade-off and has no central component. Our novel approach distributes blocks over multiple blockchains. Hydra makes a trade-off between transaction throughput and finality, the time it takes to stabilize the record of a transaction in the blockchain. We rigorously analyze the double spend attack in a multiple-blockchain protocol. Our analysis shows that the number of transactions per second can be increased significantly while finality is within acceptable boundaries.