What is it about?
Blockchain technologies are increasingly used in important real-world systems such as financial platforms, supply chains, digital identity services, and other forms of digital infrastructure. The security of these systems depends on cryptographic techniques that were designed for today’s classical computers. However, advances in quantum computing could eventually break some of these cryptographic foundations, creating new security risks for blockchain networks. If blockchain systems are not designed to withstand quantum attacks, future adversaries could potentially gain advantages in mining, forge digital signatures, or disrupt the consensus process that keeps distributed ledgers trustworthy. This could undermine confidence in blockchain-based financial systems and other critical digital services. This paper helps address this challenge by reviewing and organizing recent research on quantum-resistant blockchain consensus protocols. By analyzing current approaches, identifying their strengths and limitations, and highlighting open research problems, the study provides guidance for researchers and practitioners working to design blockchain systems that can remain secure in the age of quantum computing.
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Why is it important?
Research on quantum-resistant blockchain consensus protocols has grown rapidly in recent years, but the field remains scattered across many independent proposals and approaches. As a result, it can be difficult for researchers and practitioners to understand how these designs relate to one another or what progress has been made. This paper provides one of the first systematic overviews focused specifically on blockchain consensus in the context of quantum computing. It organizes existing proposals into clear categories based on their security assumptions and design principles, including approaches based on post-quantum cryptography, information-theoretic techniques, and quantum communication methods. By bringing these ideas together in a structured analysis, the paper highlights key patterns, limitations, and research gaps across the current literature. This perspective helps clarify the direction of the field and provides a foundation for future work on building blockchain consensus mechanisms that can withstand the challenges posed by quantum technologies.
Perspectives
One aspect that makes this work distinctive is the way it examines quantum-resistant blockchain consensus protocols through the cryptographic assumptions that underpin them. Rather than simply cataloging proposed protocols, the study organizes them according to the type of security foundations they rely on, including post-quantum cryptographic primitives, information-theoretic approaches, and protocols based on quantum communication. During the review, it became clear that many proposed systems rely on assumptions that are not always carefully justified. Several protocols lack formal security proofs, while others rely on hardness assumptions that hold only in the worst case rather than on average. By highlighting these issues and organizing the literature around the underlying security assumptions, this work aims to provide a clearer framework for evaluating current proposals and guiding the development of more rigorous quantum-resistant consensus designs.
Aleck Nash
Read the Original
This page is a summary of: SoK: Blockchain Consensus in the Quantum Age, August 2025, ACM (Association for Computing Machinery),
DOI: 10.1145/3709016.3737798.
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