Due to the need to maintain confidentiality, redundancy, and openness, the usage of Blockchain and other DLTs has dramatically advanced in recent years, and is being recommended for various applications. In blockchain, these capabilities are supplied by means of hash functions and public-key encryption. However, the rapid development of quantum computation in the near future has opened the door to the Grover and Shor algorithms. These algorithms challenge both public and hash encryption, causing blockchains to redesign and use quantum attack-tolerant cryptosystems; this produces cryptosystems which are considered post-quantum cryptosystems, which are quantum-resistant. This paper reviews current scientists on quantum blockchain for such purposes. In addition, the major challenges are studied with the most important post-quantum blockchain systems. In addition, the most promising post quantum signature encryption and digital blockchain signature schemes are detailed in terms of the functionality and durability of the most promising public signatures. In this article, researchers and developers in blockchain have an extensive perspective and practical advice on post-quantum blockchain protection.
Due to the need to maintain confidentiality, redundancy, and openness, the usage of Blockchain and other DLTs has dramatically advanced in recent years, and is being recommended for various applications. In blockchain, these capabilities are supplied by means of hash functions and public-key encryption. However, the rapid development of quantum computation in the near future has opened the door to the Grover and Shor algorithms. These algorithms challenge both public and hash encryption, causing blockchains to redesign and use quantum attack-tolerant cryptosystems; this produces cryptosystems which are considered post-quantum cryptosystems, which are quantum-resistant. This paper reviews current scientists on quantum blockchain for such purposes. In addition, the major challenges are studied with the most important post-quantum blockchain systems. In addition, the most promising post quantum signature encryption and digital blockchain signature schemes are detailed in terms of the functionality and durability of the most promising public signatures. In this article, researchers and developers in blockchain have an extensive perspective and practical advice on post-quantum blockchain protection.
Classical blockchain cryptographic primitives are susceptible to quantum computing technology due to its unprecedented growth because it has the potential to make current blockchain encryption techniques obsolete against quantum attacks. Shor algorithm can perform transactional hijacking and forge digital signatures to impersonate blockchain users. On the other hand, Grover algorithm can perform 51% attack and can accelerate brute force attack by detecting hash collisions to replace the blocks of a blockchain. With the advent of this threat, in attempt to mitigate the effects of quantum attacks on blockchain technology, the concept of post-quantum cryptography (PQC) or quantum resistant cryptography (QRC) has emerged. PQC involves cryptographic algorithms or cryptosystems that are robust against quantum attacks and are also applicable in blockchain for post quantum decentralization. In this article, we provide a brief overview of quantum threats to classical blockchain technology. We identify and discuss some important requirements for the implementation of PQC. Moreover, we also identify and explain notable unresolved challenges in implementing PQC algorithms. We also determine critical research questions for each identified challenge that are imperative to confer and requires discussion and interpretation by the researchers of this field.
Classical blockchain cryptographic primitives are susceptible to quantum computing technology due to its unprecedented growth because it has the potential to make current blockchain encryption techniques obsolete against quantum attacks. Shor algorithm can perform transactional hijacking and forge digital signatures to impersonate blockchain users. On the other hand, Grover algorithm can perform 51% attack and can accelerate brute force attack by detecting hash collisions to replace the blocks of a blockchain. With the advent of this threat, in attempt to mitigate the effects of quantum attacks on blockchain technology, the concept of post-quantum cryptography (PQC) or quantum resistant cryptography (QRC) has emerged. PQC involves cryptographic algorithms or cryptosystems that are robust against quantum attacks and are also applicable in blockchain for post quantum decentralization. In this article, we provide a brief overview of quantum threats to classical blockchain technology. We identify and discuss some important requirements for the implementation of PQC. Moreover, we also identify and explain notable unresolved challenges in implementing PQC algorithms. We also determine critical research questions for each identified challenge that are imperative to confer and requires discussion and interpretation by the researchers of this field.
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.
Quantum-resistant blockchains refer to cryptographic processes that are resistant to attacks via quantum computers. Present public-key algorithms depend on the difficulty of deciphering the discrete log and factorization problem of large prime numbers. Shor's algorithm can be used to break the hash signatures by quantum computers. Therefore, it is necessary for the development of a post-quantum secure signature scheme or quantum-resistant blockchain for post-quantum blockchain security. This chapter will discuss the impact quantum computers are predicted to have on public key cryptography based on the following topics: quantum computers, public key cryptography, quantum threat to PKI, Shor's and Grover's algorithms, post-quantum cryptography, and quantum-resistant blockchain.
Amid breakthroughs in quantum computing, blockchain systems are experiencing a dual-track evolution characterized by threats from quantum attacks and empowerment through quantum technologies. Traditional blockchain architectures, which rely on public-private key cryptography and hash functions, face systemic risks to core functions such as transaction integrity verification and consensus security when exposed to quantum attacks. This paper systematically analyzes and compares two distinct technical approaches in the field of quantum-secure blockchain: post-quantum blockchain and quantum blockchain. The former enhances existing systems by integrating post-quantum cryptographic algorithms to resist quantum threats, aiming for a smooth transition from current architectures. The latter reconstructs distributed ledger technology based on quantum information properties such as entanglement, forming novel architectures involving quantum key distribution networks, quantum digital signatures, and quantum consensus algorithms. The feasibility and development potential of these approaches are examined in application scenarios such as industrial IoT. A comparative analysis is conducted on their technical constraints and implementation challenges from the perspectives of transaction efficiency, security model validation, and standardization maturity. This lays a foundation for future empirical research. Finally, potential development paths are discussed, and targeted research directions such as diversified migration and dynamic hybrid strategies are proposed to guide further studies.
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.