TLDR

  • Experts indicate that quantum computers could be decades away from cracking Bitcoin’s encryption.
  • The “collect now, decrypt later” threat means public keys are already at risk.
  • 25%-30% of Bitcoin holdings are vulnerable because their public keys are already visible on the blockchain.
  • The cryptocurrency community is gearing up with quantum-resistant technology to protect against future threats.

Advancements in quantum computing are sparking concerns about the security of cryptocurrencies—especially Bitcoin. However, while experts agree that quantum computers capable of breaching Bitcoin’s cryptography won’t arrive by 2026, the situation presents a new challenge for the crypto space. Instead of an immediate crisis, the current risk lies in the “collect now, decrypt later” practice: malicious actors gather encrypted data today to decode it in the future once quantum technology becomes powerful enough.

The “Collect Now, Decrypt Later” Threat

Even though quantum computing is still years from gaining the ability to break today’s cryptography, its potential danger is more prominent than ever. Experts warn that adversaries may already be collecting sensitive data—including public keys—that could later be decrypted using quantum tools.

According to Leo Fan, co-founder of Cysic, one scenario involves attackers downloading large volumes of on-chain data to store for future quantum analysis. These attackers focus on gathering public keys, which—once quantum computing advances sufficiently—could be used to derive private keys. When quantum systems can decrypt data, previously captured information may be exposed, posing a severe risk to current blockchain systems.

 

Moreover, estimates suggest up to 30% of all Bitcoin is held in addresses whose public keys are already exposed. This vulnerability leaves millions of Bitcoin susceptible to future attacks, further emphasizing the need to prepare for quantum risks today.

Expert Opinions on the Quantum Threat Timeline

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

With current quantum devices only able to handle hundreds or thousands of qubits, they are far from running complex cryptanalytic algorithms like Shor’s algorithm—needed to crack cryptographic systems.

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

Preparing for a Quantum Future

Despite the remote chance of a quantum attack in 2026, the crypto community is taking proactive steps to safeguard against future risks. A key recommendation is to minimize exposure by avoiding Bitcoin address reuse. This tactic keeps public keys hidden until funds are spent, reducing the chance of them being collected for future decryption.

Furthermore, there is growing momentum toward developing quantum-resistant cryptographic alternatives. Experts are working to replace Bitcoin’s current signature system with quantum-resistant ones that better withstand future quantum machines. Some companies—like Qastle—already integrate post-quantum encryption into their systems; Qastle aims to protect wallets by upgrading cryptography without extra hardware.

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