Sharding-Based Proof-of-Stake Blockchain Protocols: Security Analysis

TL;DR

This paper analyzes the security of sharding-based Proof-of-Stake blockchain protocols, focusing on fault probability and security duration, supported by numerical evaluation to assess their robustness.

Contribution

It provides a detailed security analysis of sharding-based PoS protocols, including probabilistic fault assessment and security duration measurement, which was not extensively studied before.

Findings

Fault probability increases with more shards

Security duration varies based on network parameters

Numerical analysis confirms the model's effectiveness

Abstract

Blockchain technology has been gaining great interest from a variety of sectors, including healthcare, supply chain and cryptocurrencies. However, Blockchain suffers from its limited ability to scale (i.e. low throughput and high latency). Several solutions have been appeared to tackle this issue. In particular, sharding proved that it is one of the most promising solutions to Blockchain scalability. Sharding can be divided into two major categories: (1) Sharding-based Proof-of-Work (PoW) Blockchain protocols, and (2) Sharding-based Proof-of-Stake (PoS) Blockchain protocols. The two categories achieve a good performances (i.e. good throughput with a reasonable latency), but raise security issues. This article attends that analyze the security of the second category. More specifically, we compute the probability of committing a faulty block and measure the security by computing the number of years to fail. Finally, to show the effectiveness of the proposed model, we conduct a numerical analysis and evaluate the results obtained.