Bitcoin And Quantum Computing – is it a Threat?

Quantum computing is transforming from a term straight out of science fiction to an imminent threat to the security of cryptocurrencies.

A quantum computer powerful enough to break the encryption methods currently used to secure digital information, including cryptocurrencies like Bitcoin, could soon present a threat to DeFi and web3 as we know it.  

With the introductions of Google’s Willow chip in December 2024 and Microsoft’s Majorana chip in February 2025, expert predictions for the timeline for when a cryptographically relevant quantum computer (CRQC) will appear are continually being reassessed.

So  how serious is the threat of quantum computing to crypto? Let’s start by understanding the basics of quantum computing.

What is Quantum Computing?

Quantum computing takes the theoretical work of quantum physics, developed by the likes of Albert Einstein and Max Planck in the early twentieth century and applies it to modern computing, promising a completely new paradigm in processing capability. 

The computers we are familiar with today process information based on bits. A bit can only hold one of the following two values: 0 or 1. These bits can be strung together to create a piece of binary code. For example, 1000101101 would be a valid piece of binary information. 8 Bits together are also known as bytes. You can read more about bits and how they work here. 

This use of bits has been the standard model for computer processing, with computer chips sitting at the heart of computer architecture. Improvements in chip technology, therefore, place proportional limitations on improvements in computer processing known as Moore’s Law. Quantum computing changes the binary model of computer processing by exponentially increasing processing power. 

Instead of using bits, quantum computing makes use of quantum bits, or qubits in short. Using quantum principles like superposition and quantum entanglement, qubits process significantly higher amounts of information simultaneously, allowing quantum computers to solve complex problems exponentially faster than even the most powerful traditional supercomputers. 

For clarity, these qubits are incredibly delicate in nature, easily disturbed by even the slightest environmental interference like temperature changes or stray electromagnetic fields. 

This means they can quickly lose their special quantum state, leading to errors in calculations.

However, companies like IBM, Atom Computing, Google, and Microsoft are pouring millions into developing powerful new quantum chips with many more qubits, and more importantly, they’re getting better at making them reliable. 

Willow, for instance, is designed to reduce errors exponentially as the number of qubits grows, it recently performed a benchmark computation in under five minutes that would have taken the world’s fastest supercomputer 10^25 years!

Google Willow Chip. Source: Google

Maximum Qubit Counts: A Timeline

Qubit counts represent the amount of quantum bits that a particular quantum chip/computer can process at a given time. More qubits help process more information, and by extension represent greater computational power, allowing quantum computers to solve increasingly complex problems that are beyond classical computing capabilities.

Over the years there have been massive breakthroughs in qubit counts, let’s take a look at some of the maximum physical qubit counts that quantum computers have achieved.

Why Quantum Computing Matters

Quantum computing represents a profound leap forward for science and civilization. Because qubits can exist in multiple states simultaneously, a single quantum computer can explore countless solutions at once rather than stepping through them one by one. 

Google’s Willow chip’s performance hints at the ability to model complex molecules, optimise vast logistics networks or discover new materials in ways that are simply out of reach today.

If quantum computing fulfills its promise, the ripple effects could reshape entire industries, and change the world forever. 

Picture a world where new drugs are designed atom-by-atom in silico before human trials even begin. Where batteries last ten times longer because their chemistry has been simulated and optimized at the quantum level. Where global logistics networks self-optimize in real time, cutting waste and emissions drastically. 

Quantum computing could even one day help unlock new ways to help humans explore the stars.

By simulating new materials for spacecraft, optimizing deep-space mission logistics, and enabling secure quantum communication between satellites, it helps solve all kinds of complex, multivariable problems that space exploration demands. NASA is already using quantum processors to design more efficient propulsion systems and mission planning tools. 

But while quantum computing may help us reach the stars some day in the future, it also brings with it a serious, impending challenge we might face sooner than later: breaking the very encryption that secures our digital lives. 

Cryptocurrencies, in particular, rely on mathematical locks that quantum machines could one day pick. 

So, how exactly are cryptocurrencies in danger due to rapid advances in quantum tech? And are there contingency plans in place for any of these threats? Let’s find out.

Quantum Threats: Compromised Keys and Centralized Crypto Mining

Cryptocurrencies rely heavily on cryptography, complex mathematical puzzles and digital locks ensuring only rightful owners can access their funds. Cryptography secures crypto through two main pillars:

• Hashing Algorithms: These act like digital fingerprints to verify transaction integrity.
• Digital Signatures: These are what directly secure ownership, using a pair of mathematically linked keys: a public key and a private key.

Quantum computing threatens both of the above, just in different ways.

Quantum Threat 1: Breaking Digital Signatures

The most immediate and severe quantum threat comes from a quantum algorithm called Shor’s algorithm. 

This algorithm is capable of efficiently solving the complex mathematical problem that lays the foundation for the complex cryptography used to generate your public and private keys in cryptocurrencies like Bitcoin (specifically, the Elliptic Curve Digital Signature Algorithm, or ECDSA).

Put simply, a powerful enough quantum computer running Shor’s algorithm could derive your private key straight from your public key. If a hacker gains your private key, they can then control your funds, forge digital signatures, and steal all your crypto. 

So, how does this play out in real-time?

Harvest Now, Decrypt Later

Your public key can be exposed on the blockchain, particularly with older Bitcoin addresses (P2PK) or when you reuse common addresses (P2PKH) after spending from them.

This exposure makes the associated crypto vulnerable to future quantum computers. An estimated 25-30% of all Bitcoin (over 4 million BTC), including Satoshi Nakamoto’s wallet, is currently at risk.

In “Harvest Now, Decrypt Later” attacks, hackers collect exposed public key data today to decrypt and steal funds once quantum computers become available. This “legacy debt” of vulnerable coins, many from lost or inactive wallets, complicates the transition to quantum-safe cryptography.

Quantum Threat 2: Mining Centralization

Another quantum risk arises from Grover’s algorithm, which could accelerate Bitcoin mining dramatically. 

Mining involves solving cryptographic puzzles using massive computing power. Quantum computers using Grover’s algorithm could drastically outperform classical miners, potentially centralizing mining power into the hands of a few quantum-equipped groups or nations.

However, this risk is considered less immediate compared to the threats posed by Shor’s algorithm due to the high computational resources quantum mining would require.

Will Quantum Computers Break Crypto Soon?

Today’s most advanced machines, like Willow at 105 qubits and Majorana 1 with topological stability, top out at small scales and are still too noisy to threaten blockchain security. 

Microsoft Majorana Chip 1. Source: Microsoft

Predictions for the arrival of a CRQC vary, but the timelines are accelerating. Aggressive company roadmaps, from players like Fujitsu and IonQ, are targeting the development of machines with 10,000+ qubits by 2027–2030. 

Meanwhile, recent breakthroughs in algorithms have drastically reduced the estimated qubits needed to crack encryption, leading analysts to project a potential date for breaking RSA-2048 (an encryption standard that relies on a 2048-bit key to protect sensitive digital information) as early as 2030. 

A paper published by Craig Gidney, a Google Quantum AI scientist in late May 2025 suggests a 2048-bit RSA key could be cracked in under a week with a quantum computer using fewer than one million “noisy qubits” (a significant reduction from a previous estimate of 20 million qubits). 

These developments align with the firm migration deadline of 2035 set by U.S. government agencies like NIST and the NSA for a full transition to quantum-safe systems.

After that, fully mature quantum computers may force a total overhaul of digital security.

How Is the Crypto Community Responding to Quantum Threats?

The crypto industry is proactively developing quantum-resistant solutions known as Post-Quantum Cryptography (PQC). These new algorithms, designed explicitly to resist quantum attacks, are being standardized by institutions.

The U.S. National Institute of Standards and Technology (NIST) has been actively leading the global effort to standardize PQC algorithms, releasing the first three finalized standards (FIPS 203, 204, 205) in August 2024.

These also include quantum-resistant digital signatures like CRYSTALS-Dilithium, Falcon, and most recently, HQC.  

Quantum-resistant digital signatures are entirely new ways to digitally sign information, specifically designed to be unbreakable by future quantum computers. 

Unlike current signatures vulnerable to Shor’s algorithm, these new methods rely on extremely complex mathematical problems, like those found in “lattices,” that even powerful quantum computers are expected to find impossible to solve quickly. And even if these computers solve quantum lattice problems slowly, the outcome is expected to be equally bad. 

Since those standards were finalized, the global tech companies and open-source projects are now actively integrating these algorithms into software libraries, hardware, and protocols to provide “quantum-resistant” security ahead of the threat. 

For example, Apple’s iMessage and the Signal app have already integrated quantum-resistant algorithms to protect user communications from future threats. 

Source: Apple Security

Moreover, Foundational software libraries like Google’s BoringSSL and Tink are incorporating the new NIST standards, allowing developers everywhere to build quantum-resistant applications.

Bitcoin Improvement Proposals (BIPs)

The Bitcoin community is actively developing standards through Bitcoin Improvement Proposals (BIPs) to address quantum threats. 

In July 2025, a notable proposal co-authored by American Cypherpunk Jameson Lopp outlined a phased strategy to retire vulnerable legacy signature schemes by 2030, introducing quantum-resistant addresses under the proposed “Pay-to-Quantum-Resistant-Hash” (P2QRH) format.

This BIP also controversially suggests freezing funds in legacy addresses that remain unmigrated, effectively invalidating these transactions to prevent future quantum-enabled theft. P2QRH addresses utilize post-quantum cryptographic algorithms, significantly enhancing security against quantum attacks.

Reflecting on this challenge, Satoshi Nakamoto once remarked, 

“Lost coins only make everyone else’s coins worth slightly more. Think of it as a donation to everyone.” 

Echoing this sentiment, Lopp emphasizes, 

“Quantum recovered coins only make everyone else’s coins worth less. Think of it as a theft from everyone.”

Many proposed PQC implementations, like those for Bitcoin, also involve hybrid systems, combining classical cryptographic signatures with one or more PQC signatures. 

The challenge now is not just developing these solutions, but achieving the necessary widespread consensus and adoption across decentralized networks to migrate funds and infrastructure to quantum-safe standards before a powerful CRQC emerges. 

This requires a concerted effort from developers, miners, and individual users alike.

How to Secure Your Bitcoin In a Quantum Computing World

So, what does this mean for the crypto you hold right now? What will protecting digital assets like Bitcoin look like in the future?

While the core development of quantum-resistant standards is handled by cryptographers and developers, securing your funds in this new era will be a critical shared responsibility that directly impacts the network’s future.

The good news is that you don’t need to be an expert to protect yourself, but you will need to be proactive. Your primary task is to stay informed by closely following updates from your wallet provider. Ledger is already working on future-proofing your assets. It does so by closely monitoring quantum advancements and working with the blockchain community to develop quantum-resistant solutions.

Ledger signers use Secure Element chips designed to protect private keys against current threats. As the technology evolves, Ledger continues to innovate to keep your crypto safe.

When quantum-resistant addresses (like the proposed “Pay-to-Quantum-Resistant-Hash” or P2QRH) are rolled out and supported by your wallet, you will need to take action. You will have to perform a transaction to move your funds from your old addresses to the new quantum-resistant ones. 

Think of it like your bank upgrading its vaults and asking you to move your valuables into the new, more secure one; the protection only applies once you’ve made the move.

Conclusion

Though opinions differ on how rapidly quantum computing capabilities will evolve, there is growing consensus that it will fundamentally reshape scientific and technological pursuits, including the foundations of digital security. 

The fundamental values of crypto are built upon cryptographic integrity, and so, the very innovations that make quantum computing revolutionary in areas such as medicine, materials science, and space exploration also represent how urgently we need to rethink how we secure decentralized systems.

Proactive preparation is the only solution. 

Transitioning to quantum-resistant standards, re-architecting financial protocols, and ensuring broad community adoption will determine whether blockchain technology can endure in a quantum era. Far from being a distant theoretical risk, the accelerating pace of breakthroughs highlights that adaptation must begin now. 

The resilience of digital value and, by extension, trust in emerging decentralized economies will depend on how effectively this transition is embraced before a cryptographically relevant quantum computer arrives. Finally, in a quantum driven world, machine learning models become smarter and more efficient, and encryption schemes could evolve to be quantum-safe and more private by design.

By staying informed and adopting quantum-safe practices, you can secure your crypto investments against future threats. Specifically, when it comes to crypto security, Ledger is committed to staying ahead of the curve to provide future-proof protection against tomorrow’s threats. Keep learning! If you enjoy getting to grips with crypto and blockchain, check out our School of Block video Smart Contracts for Beginners.

Keep learning! If you enjoy getting to grips with crypto and blockchain, check out our School of Block video Smart Contracts for Beginners.