Deconstructing the Blockchain to Approach Physical Limits

TL;DR

This paper introduces Prism, a proof-of-work blockchain protocol designed to approach the physical network limits by optimizing throughput, latency, and security, and systematically deconstructs blockchain functionalities to maximize performance.

Contribution

The paper presents Prism, a novel blockchain protocol that achieves near-physical limits in throughput and latency while maintaining security and total ordering, based on a systematic deconstruction of blockchain functionalities.

Findings

Achieves security against up to 50% adversarial hashing power

Attains optimal throughput proportional to network capacity C

Provides confirmation latency proportional to propagation delay D

Abstract

Transaction throughput, confirmation latency and confirmation reliability are fundamental performance measures of any blockchain system in addition to its security. In a decentralized setting, these measures are limited by two underlying physical network attributes: communication capacity and speed-of-light propagation delay. Existing systems operate far away from these physical limits. In this work we introduce Prism, a new proof-of-work blockchain protocol, which can achieve 1) security against up to 50% adversarial hashing power; 2) optimal throughput up to the capacity C of the network; 3) confirmation latency for honest transactions proportional to the propagation delay D, with confirmation error probability exponentially small in CD ; 4) eventual total ordering of all transactions. Our approach to the design of this protocol is based on deconstructing the blockchain into its basic functionalities and systematically scaling up these functionalities to approach their physical limits.