Bitcoin’s Quantum Risk Looms—But Experts Say No Immediate Threat

Quantum computing could one day crack Bitcoin's cryptographic armor—but that day isn't today.

The ticking clock on cryptography

Every Bitcoin transaction relies on encryption that today's computers can't break. Quantum machines, theoretically, could shred that security in minutes. It's a known vulnerability baked into the system's design.

Why the panic is premature

Leading cryptographers and blockchain developers aren't losing sleep. The consensus? Practical, large-scale quantum computers capable of this attack remain decades away. The crypto community has time to adapt—and post-quantum cryptography solutions are already in development.

The real threat isn't the tech

The bigger risk might be human psychology. Fear of a distant quantum future could spark sell-offs long before any machine poses a real danger—classic market panic over a problem Wall Street can't yet monetize.

Bitcoin faces a future test, but for now, the network's biggest enemies are still volatility, regulation, and good old-fashioned greed.

TLDR

• Quantum computers may be decades away from breaking Bitcoin encryption, experts say.
• The “harvest now, decrypt later” threat means public keys are already vulnerable.
• 25%-30% of Bitcoin funds are exposed due to public keys already on-chain.
• Crypto community prepares with quantum-resistant tech to safeguard against future risks.

The growing advancement of quantum computing has raised concerns over the security of cryptocurrencies, especially Bitcoin. However, while experts agree that quantum computers capable of breaking Bitcoin’s cryptography are not expected by 2026, the situation presents an emerging challenge for the crypto community. Instead of an immediate collapse, the current risk lies in the practice of “harvest now, decrypt later,” where malicious actors gather encrypted data today with the intent to decrypt it in the future once quantum technology becomes powerful enough.

The “Harvest Now, Decrypt Later” Threat

Although quantum computing is still years away from achieving the capabilities needed to break current cryptography, its potential threat looms larger than ever. Experts caution that adversaries may already be collecting sensitive data, including public keys, which could later be exposed to quantum-enabled decryption.

According to LEO Fan, co-founder of Cysic, one scenario involves attackers downloading large amounts of on-chain data to store for future quantum analysis. These attackers are focused on gathering public keys, which, when quantum computing advances sufficiently, could be used to derive private keys. Once quantum systems are capable of decrypting data, previously captured information could be exposed, posing a severe risk to current blockchain systems.

https://twitter.com/Gxi_io/status/2002956006960365926?s=20 

Moreover, estimates suggest that up to 30% of all Bitcoin is stored in addresses whose public keys are already exposed. This vulnerability leaves millions of Bitcoin susceptible to future attacks, further underlining the importance of preparing for quantum risks today.

Expert Opinions on the Quantum Threat Timeline

Experts largely agree that a widespread threat to cryptocurrency in 2026 from quantum computing is unlikely. Sofiia Kireieva, blockchain R&D expert at Boosty Labs, explains that current quantum machines are not capable of breaking the elliptic curve digital signature algorithm (ECDSA) used by Bitcoin.

With current quantum devices only capable of handling hundreds or thousands of qubits, they are far from being able to run DEEP cryptanalytic algorithms like Shor’s algorithm that could crack cryptographic systems.

Clark Alexander, co-founder of Argentum AI, shares a similar sentiment, emphasizing that although advancements are being made, the commercial use of quantum computers is still extremely limited. He further argues that even if quantum machines reach a level of sophistication, classical computing might still pose a more immediate threat to encryption systems. As quantum technology evolves, both quantum and conventional computing will need entirely new algorithms to break public-key cryptography.

Preparing for a Quantum Future

Despite the remote possibility of a quantum attack in 2026, the crypto community is taking proactive steps to safeguard against future risks. One of the primary recommendations is to minimize exposure by avoiding the reuse of bitcoin addresses. This tactic helps keep public keys hidden until funds are spent, reducing the chances of them being harvested for future decryption.

Furthermore, there is growing momentum toward developing quantum-resistant cryptographic alternatives. Experts are working on replacing Bitcoin’s current signature system with quantum-resistant ones that can better withstand the capabilities of future quantum machines. Some companies are already integrating post-quantum encryption into their systems, such as Qastle, which aims to protect wallets by upgrading cryptography without the need for additional hardware.

In November 2025, cryptography experts presented a plan for introducing quantum-resistant technologies in Bitcoin, signaling a shift towards preparing for the inevitable rise of quantum computing.