The rise of quantum computing poses significant threats to the cryptographic underpinnings of blockchain technologies, particularly smart contracts, which automate and secure decentralised agreements. This study investigates these quantum vulnerabilities, focusing on the potential of algorithms like Shor's to compromise widely used cryptographic systems such as ECDSA, and evaluates emerging post-quantum solutions, including lattice-based cryptography and Quantum Key Distribution (QKD), to ensure smart contract resilience. Through theoretical analysis and simulations, we demonstrate that over 98% of current smart contracts could be vulnerable to quantum attacks within the next decade, while quantum-resistant protocols offer viable countermeasures despite performance trade-offs. By integrating quantum enhancements and synthesising recent advancements in Web 3.0 and IoT contexts, this review not only highlights the urgency of transitioning to quantum-secure frameworks but also charts a path for future research to maintain the integrity and efficiency of blockchain ecosystems in the quantum era.
The rise of quantum computing poses significant threats to the cryptographic underpinnings of blockchain technologies, particularly smart contracts, which automate and secure decentralised agreements. This study investigates these quantum vulnerabilities, focusing on the potential of algorithms like Shor's to compromise widely used cryptographic systems such as ECDSA, and evaluates emerging post-quantum solutions, including lattice-based cryptography and Quantum Key Distribution (QKD), to ensure smart contract resilience. Through theoretical analysis and simulations, we demonstrate that over 98% of current smart contracts could be vulnerable to quantum attacks within the next decade, while quantum-resistant protocols offer viable countermeasures despite performance trade-offs. By integrating quantum enhancements and synthesising recent advancements in Web 3.0 and IoT contexts, this review not only highlights the urgency of transitioning to quantum-secure frameworks but also charts a path for future research to maintain the integrity and efficiency of blockchain ecosystems in the quantum era.
Quantum computers pose a significant threat to blockchain technology’s security, which heavily relies on public-key cryptography and hash functions. The cryptographic algorithms used in blockchains, based on large odd prime numbers and discrete logarithms, can be easily compromised by quantum computing algorithms like Shor’s algorithm and its future qubit variations. This survey paper comprehensively examines the impact of quantum computers on blockchain security and explores potential mitigation strategies. The survey focuses on the quantum security of blockchain’s fundamental building blocks, including digital signatures, hash functions, consensus algorithms, and smart contracts. We analyze the vulnerabilities introduced by quantum computers and discuss potential countermeasures and enhancements to ensure the integrity and confidentiality of blockchain systems. Furthermore, we investigate the quantum attack surface of blockchains, identifying potential avenues for exploiting quantum computing to strengthen existing attacks. We emphasize the need for developing quantum-resistant defenses and explore solutions for mitigating the threat of quantum computers to blockchains, including the adoption of quantum and post-quantum blockchain architectures. The paper also discusses the limitations of current efforts, such as the computational overhead of post-quantum algorithms and the practical challenges in real-world deployment, illustrated through case studies of Bitcoin and Ethereum. Future research directions include developing scalable quantum-resistant blockchain protocols, optimizing cryptographic implementations for embedded devices, and establishing standardized security frameworks to mitigate emerging quantum attacks.
The convergence of Quantum Computing and Blockchain marks a transformative step in secure distributed systems, offering immense potential and serious security challenges. Quantum algorithms like Shor’s and Grover’s threaten classical cryptographic foundations such as ECC and symmetric key systems, making current blockchains vulnerable. This study explores these vulnerabilities and proposes a hybrid quantum-secure blockchain architecture that integrates post-quantum cryptography such as lattice-based and hash-based algorithms with traditional methods for backward compatibility and efficiency. It also highlights how quantum technologies can enhance blockchain performance through faster consensus and smart contract optimization. The paper concludes that adopting hybrid quantum-resistant mechanisms is vital for ensuring blockchain security, scalability, and resilience in the post-quantum era.
Blockchain ecosystems and platforms form a critical foundation for national digital economies worldwide. However, recent advancements in quantum computing, exemplified by breakthroughs from IBM and other leading developers, reveal that these systems may no longer guarantee stability and security against emerging quantum-enabled attacks. The increasing feasibility of such threats, commonly referred to as the “quantum threat,” poses unprecedented risks to the integrity, confidentiality, and reliability of blockchain infrastructures. In response, several technologically advanced countries have initiated efforts to anticipate and mitigate potential quantum cyberattacks. Ensuring the quantum resilience of blockchain systems necessitates novel approaches beyond conventional information security methods. Unlike traditional protections, these approaches aim to prevent systemic failures even under quantum-enabled adversarial conditions. The study identifies and systematizes the main directions for achieving quantum resilience, including post-quantum cryptographic primitives, modified quantum algorithms, and hybrid quantum–classical security models. The review highlights how progress in superconducting, ionic, photonic, and neutral-atom quantum platforms reshapes the threat landscape. A distinctive contribution of this work lies in its integrative perspective — linking cryptographic, architectural, and ecosystem-level aspects of blockchain sustainability under quantum threats. The proposed framework emphasizes combining post-quantum cryptography, quantum-safe protocols, and cross-domain coordination between quantum computing and cybersecurity research. Given the rapidly advancing nature of quantum technologies, the findings presented here not only reflect the current state of the field but also outline strategic directions for developing adaptive, quantum-resilient blockchain systems, including dynamic algorithmic frameworks, formal verification of quantum-resistant smart contracts, and simulation of blockchain protocols against quantum adversary models.
The emergence of quantum computing poses a significant threat to the security of blockchain protocols, primarily due to the vulnerability of current cryptographic algorithms to quantum attacks. This vulnerability jeopardizes the integrity of data and assets stored on blockchain networks, which currently hold hundreds of billions of dollars in cryptocurrencies and other digital assets. To mitigate this risk, various proposals and solutions have been presented in the literature. However, most existing proposals are either theoretical, rely on large quantum key distribution (QKD) networks, or advocate for the development of new quantumresistant blockchain networks from scratch. Despite the understanding of the quantum threat and potential solutions, practical implementations are scarce. A recent survey paper addresses this gap by proposing an end-to-end framework for achieving postquantum resistance in existing blockchain networks. The framework, outlined in the survey, is compatible with Ethereum-based networks and offers practical solutions for key generation, secure communication between nodes, and transaction verification. Notably, the framework utilizes quantum entropy for key generation, and post-quantum TLS connections, and introduces post-quantum signatures in transactions. Additionally, it incorporates on-chain verification mechanisms using Solidity smart contracts and modified EVM Opcode. This chapter represents a significant contribution to the field by providing a comprehensive overview of existing solutions and proposing a practical framework for enhancing blockchain security against quantum threats.
Quantum computers pose a significant threat to blockchain technology's security, which heavily relies on public-key cryptography and hash functions. The cryptographic algorithms used in blockchains, based on large odd prime numbers and discrete logarithms, can be easily compromised by quantum computing algorithms like Shor's algorithm and its future qubit variations. This survey paper comprehensively examines the impact of quantum computers on blockchain security and explores potential mitigation strategies. We begin by surveying the existing literature on blockchains and quantum computing, providing insights into the current state of research. We then present an overview of blockchain, highlighting its key components and functionalities. We delve into the preliminaries and key definitions of quantum computing, establishing a foundation for understanding the implications on blockchain security. The application of blockchains in cybersecurity is explored, considering their strengths and vulnerabilities in light of evolving quantum computing capabilities. The survey focuses on the quantum security of blockchain's fundamental building blocks, including digital signatures, hash functions, consensus algorithms, and smart contracts. We analyze the vulnerabilities introduced by quantum computers and discuss potential countermeasures and enhancements to ensure the integrity and confidentiality of blockchain systems. Furthermore, we investigate the quantum attack surface of blockchains, identifying potential avenues for exploiting quantum computing to strengthen existing attacks. We emphasize the need for developing quantum-resistant defenses and explore solutions for mitigating the threat of quantum computers to blockchains, including the adoption of quantum and post-quantum blockchain architectures. By examining vulnerabilities and discussing mitigation strategies, we aim to guide researchers, practitioners, and policymakers in developing robust and secure blockchain systems capable of withstanding advancements in quantum computing technology.
Quantum computing is progressing at a fast rate and there is a real threat that classical cryptographic methods can be compromised and therefore impact the security of blockchain networks. All of the ways used to secure blockchain like Rivest–Shamir–Adleman (RSA), Elliptic Curve Cryptography (ECC) and Secure Hash Algorithm 256-bit (SHA256) are the characteristic of the traditional cryptographic techniques vulnerable to attack by quantum algorithms: Shor’s and Grover’s algorithms: can efficiently break asymmetric encryption and speed up brute force attacks. Because of this vulnerability, there exists a need to develop an advance quantum resilient blockchain framework to protect the decentralized ledgers from the future threats of the quantum. This research proposes Post-Quantum Cryptography (PQC), Quantum Key Distribution (QKD) and Quantum Random Number Generation (QRNG) as a formidable architectural integration, to fortify security of blockchain. Classical encryption is replaced with PQC, QKD with secure key exchange by detecting eavesdropping, and QRNG with improving cryptographic randomness to remove the predictable key vulnerability. Only with a small loss of transaction efficiency, we increase transaction encryption accuracy, key exchange security, and resistance to quantum attacks. In this quantum enhanced blockchain design, the idea is to preserve the decentralization, transparency and security and at the same time overcome the future quantum threat. By going through rigorous analysis and comparative evaluation, we demonstrate that the approach saves blockchain networks from the emerging quantum risks to make sure that the decentralized finance, smart contracts and cross chain transactions.