Quantum-Safe Cryptography for Blockchain: Securing Cryptocurrencies Against Quantum Computing Threats"

Verónica Fernández, Amalia Beatriz Orue, David Arroyo

Yuanyi Zhang

Cryptocurrencies have gained significant importance in the financial market, and the emergence of quantum computers has raised concerns about their impact on cryptocurrency systems.This article aims to analyze these impacts, focusing primarily on the effects on the mining process, threats to blockchain security, and potential solutions to mitigate these effects.Through an extensive review of articles and theoretical research, this article uncovers significant potential effects on cryptocurrency systems resulting from quantum computing.The article highlights that the advent of quantum computing could lead to a drastic acceleration of the mining process, operating in quadratic time.Additionally, it raises concerns about the security vulnerabilities that quantum attacks pose to blockchain systems, as Shor's algorithm poses a considerable threat to the cryptographic mechanisms upon which cryptocurrencies rely.Grover's algorithm, on the other hand, has the potential to significantly reduce the time and energy consumption involved in mining.Although new cryptographic methods, such as Post-Quantum Cryptography, have been proposed to withstand quantum attacks, their effectiveness can only be theoretically evaluated until practical quantum computers become available.At present, the impact of quantum computing on the real world remains limited due to the nascent state of quantum technology.However, with IBM's plan to develop a 100,000-qubit system by 2033, the potential threats to cryptocurrency systems cannot be disregarded.

Tamheed Nazir, Farheen Siddiqui

Sarah Alghamdi, Sultan Almuhammadi

Cryptocurrency are decentralized digital money systems built on blockchain technology. The transactions are secured in these system using digital signatures based on public-key cryptography. Public-key cryptographic algorithms used for digital signatures, such as ECDSA, are vulnerable to quantum attacks. With over 2 trillion dollars market capitalization, the cryptocurrency industry will be at high risk in the Quantum Era. This paper evaluates the security of today's cryptocurrency blockchains under quantum attacks. It also reviews some of the proposed solutions to protect blockchains in the Quantum Era. Moreover, it presents a number of post-quantum digital signature schemes used to build quantum-safe blockchains. The result of this study shows that only a small portion of cryptocurrency can resist quantum attacks, while most of the cryptocurrencies used today are vulnerable to quantum attacks, with more than 99.8% of the total cryptocurrency market cap remains at risk. Useful recommendations are provided as a result of this study.

Jitendra Sandu Adi Mutha

With the advent of quantum computing, cryptocurrencies that rely on blockchain technology face mounting cryptographic vulnerabilities. This paper presents a comprehensive literature review evaluating how quantum algorithms—specifically Shor’s and Grover’s—could disrupt the foundational security mechanisms of cryptocurrencies. Shor’s algorithm poses a threat to public-key cryptographic schemes by enabling efficient factorization and discrete logarithm solving, thereby endangering digital signature systems. Grover’s algorithm undermines hash-based functions, increasing the feasibility of 51% attacks and hash collisions. By examining the internal mechanisms of major cryptocurrencies such as Bitcoin, Ethereum, Litecoin, Monero, and Zcash, this review identifies specific vulnerabilities in transaction and consensus processes. It further analyses the current hardware limitations of quantum systems and estimates when such attacks could become feasible. In anticipation, it investigates countermeasures including Post-Quantum Cryptography (PQC), Quantum Key Distribution (QKD), and protocol-level modifications such as memory-intensive proof-of-work algorithms and multi-signature schemes. The discussion integrates recent advancements in quantum error correction, hardware scalability, and NIST-standardized cryptographic algorithms. This review concludes that while quantum computers are not yet advanced enough to pose an immediate threat, proactive integration of quantum-resistant solutions is essential. The findings underscore the urgent need for cryptocurrencies to adopt post-quantum cryptographic standards to preserve the decentralized trust, integrity, and security that define blockchain-based digital cryptocurrencies.