In This Article
Quantum computing is cited as one of the biggest threats to cryptocurrency and, of course, blockchains. The rapid advancements in computing technology have raised concerns about the security of Bitcoin (BTC), a blockchain network renowned for its robust security and hack-proof nature.
In 2025, experts are asking if quantum computers can hack Bitcoin. And it seems like the opinions are divided. One school of researchers says we are only a few years away from quantum computers hacking Bitcoin, while another school of experts say it’s a far-stretched thought. To set the record straight, 99Bitcoins did its investigation. We considered all the factors, including the threats that crypto investors should be aware of; we also reached out to several experts for their insights.
So, in this article, we have covered everything you need to know about quantum computers’ threats to BTC. Not just that, we have evaluated Bitcoin’s security model to assess if hacking is even possible. We have also discussed the latest innovations within the computing sector. Sit back, relax and keep reading.
Are Quantum Computers a Threat to Bitcoin: Summary
The threat of quantum computing to Bitcoin and other cryptocurrencies lies in the technology’s ability to solve complex mathematical problems at speeds that are currently beyond the ability of classical computers.
Cryptocurrency experts fear a future when quantum computers will be powerful enough to hack Bitcoin by breaking the encryption standards that secure blockchains. BlackRock, the world’s largest asset manager, has already flagged the risk of quantum computers to Bitcoin in its iShares Bitcoin Trust ETF filing. With cryptocurrency adoption rising, the world seems to be contemplating quantum-resistant solutions.
Can Quantum Computers Hack Bitcoin: A Deep Dive
Bitcoin is the world’s oldest and most valuable cryptocurrency. At a market cap of over $2.16T, Bitcoin is valued higher than most global companies and multi-national corporations. At the time of writing, only gold, Microsoft, NVIDIA, Apple, and Amazon had a higher market cap than Bitcoin. The cryptocurrency boasts more than 106 million global investors, with an increasing number of governments and corporate institutions adding Bitcoin to their treasuries. If quantum computing becomes powerful enough to hack Bitcoin, the loss of wealth and the negative impact on the global financial system will be catastrophic.
Key Takeaways
What Are Quantum Computers?
Quantum computing is an emerging computer science technology that has the potential to solve complex problems beyond the ability of high-performance classical computers.
Classical computers use binary bits (zeros and ones) to store and process data. On the other hand, quantum computers can encode extra data by using quantum bits or qubits. According to IBM, qubits are created by manipulating and measuring quantum particles, which are the smallest known building blocks in the universe. When combined, qubits can scale exponentially.
Quantum computing technology was first proposed in the 1980s. The technology is still in its early stages of development in 2025. Researchers are currently developing various types of qubits to suit specific applications. They are:
Now, it’s crucial first to understand what’s happening in the quantum computing field before we evaluate its risks to Bitcoin. Before we begin our comparison study, let’s sum up the biggest developments within the quantum computing sector:
Bitcoin & Blockchain Technology
Bitcoin is a peer-to-peer (P2P) electronic cash system that allows anyone to make online payments directly to the other party without going through intermediaries such as banks. Payments are made using a namesake cryptocurrency called BTC. An underlying blockchain tracks transactions and account balances. To learn more about it, consider reading our ‘What is Bitcoin’ guide.
A blockchain is a distributed and immutable ledger that records transactions securely and transparently. Its name comes from the way it stores transactions, which are compiled into groups called blocks. Each block is linked sequentially to form a chain of blocks.
Bitcoin enables decentralized payments with the help of a group of network participants known as miners. Anyone with the required hardware can become a miner. Miners’ primary function is to verify, process, and finalize transactions. For adding new blocks to the Bitcoin blockchain, miners are rewarded with newly minted BTC. These rewards ensure that the mining community is incentivized to act honestly.
The decentralized and regionally distributed nature of the Bitcoin mining community ensures that miners do not collude to defraud the Bitcoin blockchain. Since Bitcoin blocks are only finalized when the mining community comes to a consensus about the authenticity of a new block, miners keep each other in check.
However, if attackers gain control of more than 51% of Bitcoin’s computing power, they can manipulate the blockchain to their advantage. As explained by Bitcoin creator Satoshi Nakamoto in the whitepaper,
The system is secure as long as honest nodes collectively control more CPU power than any cooperating group of attacker nodes.
Understanding Bitcoin’s Security Model
Bitcoin is secured by a decentralized network of miners and a technology called the proof-of-work (PoW) consensus mechanism. In the PoW consensus mechanism, Bitcoin’s miners compete with each other to solve complex mathematical puzzles by expending computing power. The first miner to solve the puzzle is rewarded with the chance to create the next Bitcoin block.
The new, proposed block is only accepted if the majority of miners accept its validity. Once the new block is added to the Bitcoin blockchain, the miner is rewarded with newly mined BTC coins. As more blocks are added to the tail end of the Bitcoin blockchain, it becomes increasingly complex to modify past blocks, as an attacker will have to redo the PoW of all the blocks before it.
Within Bitcoin’s PoW consensus mechanism, the SHA-256 cryptographic hash function is used to secure transactions. SHA-256 hash function allows miners to verify the authenticity of Bitcoin transactions. It also ensures that transmitted messages within the blockchain are only received by authorized parties so that hackers cannot modify messages. As per the Bitcoin whitepaper,
If a majority of CPU power is controlled by honest nodes, the honest chain will grow the fastest and outpace any competing chains. To modify a past block, an attacker would have to redo the proof-of-work of the block and all blocks after it and then catch up with and surpass the work of the honest nodes.
Bitcoin wallets are protected by elliptic curve cryptography (ECC) to encrypt and decrypt wallet addresses. ECC provides a way to generate public-private keys, which are used to send and receive Bitcoin to/from crypto wallet addresses.
Is Bitcoin Safe From Quantum Computers?
At the moment, Bitcoin miners use application-specific integrated circuit (ASIC) chips to mine Bitcoin. These chips are optimized to solve cryptographic proof-of-work puzzles. Experts within the industry fear that the introduction of quantum computers will kill Bitcoin and other cryptocurrencies by breaking the cryptographic algorithms that secure them.
Bitcoin’s ability to withstand quantum computing threats was put for debate again in May 2025, when Craig Gidney, a quantum research scientist, and Sophie Schmieg, a cryptography engineer at Google, published new findings that 2048-bit RSA encryption could theoretically be broken by a quantum computer with 1 million noisy qubits running for one week.
The duo said that the latest study showed a 20-fold decrease in the number of qubits from previous estimates published in 2019, indicating the fast pace of development and innovation within the quantum computing sector.
On a positive note, Gidney and Schmieg also revealed that the National Institute of Standards and Technology (NIST) has already released standard PQC algorithms that are expected to be resistant to future large-scale quantum computers.
But the question is, how can Bitcoin secure itself from quantum attacks? In 2010, Bitcoin founder Satoshi Nakamoto suggested on the Bitcoin Forum that Bitcoin could transition from the SHA-256 cryptographic algorithm to a more quantum-resistant algorithm “if SHA-256 became completely broken.”
Could Quantum Computers Actually Hack Bitcoin? 99Bitcoins Investigation
In this section, we investigate whether quantum computers are a threat to Bitcoin. To understand quantum computers vs. Bitcoin encryption, we must understand the difference between quantum computing and classical computing.
IBM explained the difference between the two by comparing computing to solving a maze puzzle. The technology company said that classical computers will use brute force techniques to solve the maze by trying every combination of paths to find the exit. Meanwhile, quantum computers will have a bird’s-eye view of the maze and will test multiple paths simultaneously to reveal the correct solution.
When we apply this analogy to solving PoW puzzles in Bitcoin mining, we learn that current ASIC-equipped miners solve PoW puzzles by calculating every mathematical combination possible. Meanwhile, quantum computer-equipped miners could solve PoW puzzles at faster rates due to their “bird’s-eye view” of the puzzle. This could result in quantum computer-equipped miners having more influence and control over the Bitcoin blockchain than miners with inferior hardware.
However, we must remember that Bitcoin is designed to increase its mining difficulty as more computational power enters the network. For context, Bitcoin’s mining difficulty adjustment was created to ensure that two Bitcoin blocks are always created about ten minutes apart.
When it comes to stealing funds from a Bitcoin address, a quantum computer could actually make that happen. According to Deloitte, quantum computers may become powerful enough to derive the private keys of a Bitcoin wallet address if its corresponding public keys are known. This would allow the quantum computer-equipped attacker to spend the coins stored within the wallet address.
Quantum computing technology is still in its early stages. According to IBM, qubits may be powerful, but are very temperamental. For qubits to function, they must be cooled to a temperature only a fraction of a degree higher than absolute zero, which is “colder than outer space.”
It could be a while before quantum computers become readily available in the market. However, D-Wave Quantum made its Advantage2 quantum computing system available to the public for commercial use in May 2025, and customers can only access it through its cloud service.
How to Prepare Yourself for a Post-Quantum World?
Honestly, true quantum threats are years away, so we don’t need to be too worried at the moment. But remember, now is a good time to take control of your crypto security. And one of the best defenses, both today and in the future, will be self-custody. Tools like Best Wallet give you exactly that control. While it’s not quantum-resistant (since no wallet is yet), this mobile wallet ensures that you keep your private keys with yourself, away from centralized servers, and it offers a seamless way to buy, sell and trade cryptos.
Real-World Quantum Attacks – Has It Happened Before?
Here are some notable known attempts to break cryptography with quantum computers:
Possibilities of Quantum Computers Hacking Bitcoin
Here is what experts are saying about the possibility of quantum computers hacking Bitcoin:
What Research Says?
BlackRock, the largest asset manager in the world by assets under management (AUM) and the issuer of Bitcoin exchange-traded funds (ETFs), flagged quantum computing risks in its regulatory filing. Quantum computing could result in the cryptography underlying the Bitcoin network becoming ineffective, compromising Bitcoin’s network security and allowing a malicious actor to steal funds from Bitcoin wallets.
According to Deloitte, all BTC coins held in reused wallet addresses can be considered vulnerable to quantum computing because of the potential capabilities of quantum computers to derive private keys from corresponding public keys.
Deloitte says the best way to protect Bitcoin from quantum computing hacks is to avoid reusing Bitcoin addresses.
The public key cannot be retrieved from the address. The public key is only revealed at the moment when the owner wishes to initiate a transaction. This means that as long as funds have never been transferred from a p2pkh address, the public key is not known and the private key cannot be derived using a quantum computer. There is a ‘but’ though! If funds are ever transferred from a specific p2pkh address (no matter what amount), the public key is revealed. From that moment on, this address is marked “used” and should ideally not be used again to receive new coins.
What Experts Say?
Chunyang Shen, co-founder of tokenized real-world asset marketplace Jarsy, told 99Bitcoins that at this moment, quantum computing does not spell an immediate end to Bitcoin, as most authorities believe that a sufficiently powerful quantum computer capable of attacking Bitcoin is likely to appear within the next 10–15 years.
Shen added that implementing post-quantum cryptography, upgrades to the Bitcoin protocol, quantum-safe wallet addresses, and avoiding reusing wallet addresses will help mitigate quantum computing risks.
Elsewhere, in an exclusive report, Presto Research reached out to Professor Isaac Kim, Assistant Professor of Computer Science at UC Davis, to help Bitcoin investors understand the risk of quantum computing.
When asked whether quantum computers could break Bitcoin wallets, Professor Kim said:
Yes, quantum computing matters to crypto because it threatens the kind of encryption that blockchains rely on, especially elliptic curve cryptography (ECC), which secures most wallets. Quantum computers could one day run Shor’s algorithm, a powerful technique for breaking ECC and recovering private keys from public ones. That means if your wallet’s public key is exposed, a future quantum attacker could steal your funds.
Professor Kim added that the “first biggest warning sign” to crypto would be when the world starts seeing quantum computers with roughly 100 logical qubits.
What Happens If a Quantum Computer Hacks Bitcoin?
Here are the possibilities if a quantum computer ever compromises Bitcoin’s cryptographic encryption:
Conclusion: Can Quantum Computers Hack Bitcoin?
Bitcoin users have to acknowledge quantum computing risks, even though experts have suggested that it will take years for the technology to pose a real threat to the cryptocurrency blockchain. However, Bitcoin developers have recognized the threats and are actively researching to protect the blockchain from these vulnerabilities.
For the time being, Bitcoiners must stay updated with the latest developments in the quantum computing and blockchain technology space to prepare themselves for such a future.
See Also:
- How to Buy Bitcoin in 2025
- 15+ Best Bitcoin Casinos to Play at in 2025
- Bitcoin Staking: How to Earn Rewards by Staking Crypto?
- Top 5 Cryptos That Can Survive Quantum Computing
- What is Metaverse: A Beginner’s Guide
- De-dollarization: What It Means for Bitcoin & Stablecoins?
References
- “Assets by Market Cap.” CompaniesMarketCap, https://companiesmarketcap.com/assets-by-market-cap.
- “Qubit.” IBM Think, https://www.ibm.com/think/topics/qubit.
- “Quantum Computing.” IBM Think, https://www.ibm.com/think/topics/quantum-computing.
- “IBM Quantum Roadmaps.” IBM, https://www.ibm.com/roadmaps/quantum/.
- “D-Wave Announces General Availability of Advantage2 Quantum Computer, Its Most Advanced and Performant System.” D-Wave Quantum, https://www.dwavequantum.com/company/newsroom/press-release/d-wave-announces-general-availability-of-advantage2-quantum-computer-its-most-advanced-and-performant-system/.
FAQs
Can quantum computers really hack Bitcoin's blockchain?
Experts believe that quantum computers could develop the ability to derive private keys from corresponding public keys and take control of funds stored in a wallet.
Why are quantum computers considered a threat to Bitcoin’s security?
Quantum computing could compromise the Bitcoin network’s cryptography, making it ineffective. This could compromise Bitcoin’s network security and allow a malicious actor to steal funds from Bitcoin wallets.
How many qubits would it take to hack Bitcoin’s encryption?
According to Professor Isaac Kim of UC Davis, the “first biggest warning sign” to crypto would be when the world starts seeing quantum computer with roughly 100 logical qubits.
When will quantum computers be powerful enough to hack Bitcoin?
Experts believe it could take years for quantum computers to be powerful enough to hack Bitcoin.
Would Bitcoin lose its value if a quantum attack occurs?
Yes, Bitcoin would lose its market value if a quantum attack occurs because investors are drawn to Bitcoin for its strong security, store-of-value property, and digital gold status.
What do experts say about the quantum threat to Bitcoin?
According to Deloitte, all BTC coins held in reused wallet addresses can be considered vulnerable to quantum computing because quantum computers have the capability to derive private keys from corresponding public keys.
Is the quantum computing threat overhyped or a real risk for Bitcoin?
Yes, quantum computing is a real threat to Bitcoin. However, the technology has not yet reached the level required to attack the underlying cryptographic encryption that secures Bitcoin.
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