Partitionable Asynchronous Cryptocurrency Blockchain

TL;DR

This paper investigates the challenges of maintaining consensus in partitioned blockchain networks, proving the problem's impossibility in asynchronous systems and proposing detector-based solutions for partition management.

Contribution

It introduces the Partitionable Blockchain Consensus Problem, proves its unsolvability in asynchronous systems, and presents a detector-based algorithm to address partitioning issues.

Findings

The problem is not solvable in asynchronous systems without additional mechanisms.

Detectors enable consensus during network partitions.

The proposed algorithm handles multiple splits, message loss, and merging scenarios.

Abstract

We consider operation of blockchain-based cryptocurrency in case of partitioning. We define the Partitionable Blockchain Consensus Problem. The problem may have an interesting solution if the partitions proceed independently by splitting accounts. We prove that this problem is not solvable in the asynchronous system. The peers in the two partitions may not agree on the last jointly mined block or, alternatively, on the starting point of independent concurrent computation. We introduce a family of detectors that enable a solution. We establish the relationship between detectors. We present the algorithm that solves the Partitionable Blockchain Consensus Problem using our detectors. We extend our solution to multiple splits, message loss and to partition merging. We simulate and evaluate the performance of detectors, discuss the implementation of the detectors and future work.