Post-Quantum Blockchain: Challenges and Opportunities

TL;DR

This paper reviews the threats quantum computing poses to blockchain security and explores the potential of Post-Quantum Cryptography to develop secure blockchain systems for the future.

Contribution

It provides a comprehensive overview of quantum threats to blockchain and discusses the challenges and opportunities in implementing Post-Quantum Blockchains.

Findings

Quantum algorithms threaten current cryptographic protocols

Post-Quantum Cryptography offers solutions for blockchain security

Future research directions are outlined for PQB development

Abstract

Blockchain is a Distributed Ledger Technology (DLT) that offers numerous benefits including decentralization, transparency, efficiency, and reduced costs. Hence, blockchain has been included in many fields. Blockchain relies on cryptographic protocols (especially public-key cryptography and hash functions) to achieve many essential sub-routines. However, the increased progress of quantum computation and algorithms has threatened the security of many traditional cryptosystems. Therefore, this represents a serious risk for the existing blockchain technology. For example, SHA-256 and the Elliptic Curve Digital Signature Algorithm (ECDSA) cryptosystems can be compromised by Shor s and Grover s quantum algorithms in the foreseeable future. Post-Quantum Cryptography (PQC) is a basic solution for resisting these quantum attacks. Applying PQC to blockchains results in creating Post-Quantum Blockchains (PQB). Thus, this paper aims to review the threats imposed by quantum computers on classical blockchain technology and provide useful guidelines on PQB security to blockchain researchers. The paper focuses on the challenges and opportunities of future work direction in this field.