July 17, 2025
Bitcoin and Quantum Computing: Understanding the Threats and Building Quantum Resistance
The Important Bits
Quantum computing poses risks to all encryption systems.
Quantum computers are currently limited, with practical applications at least 15–20 years away.
Quantum advances could compromise cryptographic systems and internet security.
Developers are exploring quantum-safe wallets and protocol upgrades to build resistance.
Global, cross-industry cooperation is essential to address quantum threats and protect the digital economy.
Introduction to quamtum computing
Quantum computers harness the power of quantum physics, with the potential to process information much faster than classical computers, which run binary code on silicon-based hardware.
The possibility of breakthroughs in quantum computing has tremendous implications for both Bitcoin and the digital economy as a whole. If quantum computers were to be perfected, they could easily break the encryption protocols that protect all digital infrastructure today. A functioning quantum computer could quickly compromise websites, banks, public utilities, hospitals, governments, and any blockchain network. Even Bitcoin, whose monumental hash rate makes it the most secure computing network in the world, would be at risk.
For the sake of the digital world we all rely on every day, it’s important that solutions are implemented as soon as possible to protect online systems from future threats.
What is quantum computing?
Quantum computing is a revolutionary technology that leverages the principles of quantum mechanics to perform computations at speeds far beyond the capabilities of classical computers. Unlike traditional computers, which use bits as units of information (represented by 0s and 1s), quantum computers use qubits, which can exist in multiple states simultaneously thanks to quantum phenomena like superposition and entanglement. This allows quantum computers to solve complex problems exponentially faster than classical systems in certain domains.
Currently, quantum computing remains in its infancy. While progress in the technology is being made, today's quantum chips are far from usable for everyday tasks. Experts estimate that practical quantum computing applications could be at least 15 - 20 years away. Quantum chips are thought to require about 1 million qubits for practical apps; whereas today’s chips have about 105 qubits.
What threats does quantum computing pose?
Quantum computing will eventually pose a significant threat to modern cryptographic systems, which rely on mathematical problems that are virtually impossible for classical computers to solve. A sufficiently powerful quantum computer could break widely used encryption methods, such as RSA and elliptic curve cryptography, undermining the security of digital communications, financial transactions, cryptocurrencies, stored data, and more.
Blockchain-based systems, including Bitcoin, rely on cryptographic algorithms for transaction validation, wallet security, and mining. Quantum computers could theoretically break these algorithms, allowing attackers to forge transactions, steal assets, manipulate smart contracts, or disrupt consensus mechanisms. This could pose an existential risk to cryptocurrencies without the implementation of effective quantum-resistant solutions. But the threat is in no way unique to crypto.
Quantum computing could also jeopardize secure communications across the internet. Protocols like HTTPS, which safeguard e-commerce platforms, online banking, and confidential communications, would become vulnerable, potentially exposing sensitive financial and personal data.
The threat is global, with financial institutions, governments, and corporations all at risk. Fortunately, powerful interests in finance and government are committed to creating quantum-resistant encryption. The financial sector and the military have a lot to lose in the face of quantum attacks, and they also have the knowledge and resources to develop the technologies needed to defend themselves. Likewise, decentralized development teams are highly incentivized to protect cryptocurrency and blockchain networks.
How real are these threats?
Marathon Digital Holdings (MARA), one of the largest publicly traded Bitcoin mining companies, believes quantum computers are decades away from being capable of breaking any kind of code, including the types of encryption that secure Bitcoin.
They point to Moore’s Law and cite expert opinions on the matter. For example, if the number of qubits in a quantum computer chip were to double every year, then perhaps around the year 2040 applications useful for breaking encryption could emerge.
Image source: introtoquantum.org
One important caveat worth highlighting is the timeframe for breaking SHA-256, Bitcoin’s proof-of-work mining algorithm. Doing so in one hour would require approximately 317 million qubits. Even extending the timeframe to five years it would still take approximately 6,000 qubits.
However, quantum computing is a highly complex technology and there’s more to the equation than simply increasing the number of qubits. Other breakthroughs in physics and mathematics would likely be needed to create functional quantum computers with practical applications. All timelines are therefore rough estimates.
Regardless, most experts agree that action needs to be taken as soon as possible to mitigate the threat. The U.S. National Security Agency (NSA) has set a deadline of 2035 for all American national security systems to adopt post-quantum encryption algorithms. This aligns with the Moore’s Law estimate cited earlier, which predicts quantum threats potentially emerging as soon as 2040. Being prepared by 2035 would ensure the threat could be mitigated well ahead of time.
What can be done today to achieve quantum resistance?
Is Bitcoin quantum resistant? The answer as of 2025 is no. But there are already solutions being developed.
For example, Bitcoin developer Hunter Beast (@cryptoquick) gave a talk at Bitcoin Amsterdam in 2024 describing his proposal for quantum-resistant public keys for Bitcoin. This would require a soft fork in the Bitcoin code, and require users to transfer their coins to new, post-quantum wallet addresses. However, the threat goes beyond wallets being protected.
If a powerful quantum computer were to come online and start mining Bitcoin, the difficulty of the process would skyrocket. Bitcoin’s difficulty adjustment is an aspect of the protocol that makes it easier or harder to mine Bitcoin depending on the amount of hash rate on the network.
When more people are mining, difficulty rises, and if less are mining, difficulty falls. This balance keeps the network running smoothly, with one block being mined every 10 minutes or so on average. A quantum computer could add so much hash rate in such a short time that it would become almost impossible for anyone else to mine Bitcoin.
As quantum computing technology advances, blockchain and cryptocurrency systems must adapt. Several potential short-term and long-term strategies are being considered that could safeguard against potential threats.
Short-Term Solutions
Various measures can be implemented today to improve quantum resistance, even before quantum computers become a practical threat. One example is the exploration of advanced cryptographic techniques, such as using Taproot scripts to create quantum-resistant wallets. These experimental approaches leverage Bitcoin’s existing protocol capabilities to enhance security against emerging quantum risks.
Blockchain projects are also taking incremental steps to future-proof their systems. For instance, some developers are integrating hybrid cryptographic methods, combining classical and quantum-resistant algorithms, to prepare for gradual transitions to post-quantum encryption standards.
Long-Term Solutions
Achieving full quantum resistance may require fundamental changes to blockchain protocols. These updates include replacing vulnerable cryptographic algorithms, such as Elliptic Curve Digital Signature Algorithm (ECDSA), with quantum-safe alternatives like lattice-based or hash-based cryptography. This transition will demand extensive testing and coordination across the decentralized ecosystem to ensure smooth implementation.
Lessons can also be drawn from projects like Solana, which claims to have already introduced quantum-resistant features into its protocol. By proactively addressing potential vulnerabilities, Solana demonstrates the feasibility of adopting quantum-resistant measures without compromising network performance.
Through a combination of short-term experiments and long-term innovations, the cryptocurrency ecosystem can prepare for a future where quantum computing becomes a reality.
The bigger picture: collaboration across industries
While media coverage often emphasizes the quantum threat in the context of cryptocurrency, the burden of developing quantum-resistant systems falls upon the technology sector as a whole. Crypto is just one aspect of a much broader industry that could one day be endangered by quantum computers. In fact, many cryptocurrencies are among the best-suited technologies to withstand attacks of any kind, with strong encryption at their core.
Although the real threat will likely not surface for at least 15 years, progress is already being made on multiple fronts, as industry leaders are taking the threat seriously. Ongoing research into quantum-safe systems demonstrates this early-days collaboration.
Universities and research institutions are working alongside governments to develop post-quantum cryptography standards, with organizations like the National Institute of Standards and Technology (NIST) helping to identify and standardize quantum-resistant algorithms.
Major corporations and financial institutions are also heavily invested in quantum security. Tech giants like IBM and Google are not only advancing quantum computing technology, but also contributing to quantum-safe encryption research. Meanwhile, financial institutions, from Wall Street banks to global payment networks like Visa and Mastercard, are actively funding and testing quantum-resistant solutions to protect their critical infrastructures.
Future outlook
As quantum computing technology evolves, the need for adaptable security measures will become increasingly urgent. Collaborative efforts between blockchain developers, governments, academia, and industry leaders can help address quantum risks effectively and ensure the resilience of digital systems. By staying ahead of emerging threats, the global community can safeguard the future of cryptocurrencies and the broader digital economy.
Further reading on quantum computing:
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