Recent advances in quantum computing have reignited concerns about the security of cryptocurrencies like Bitcoin (BTC).
Most notably, IBM (NYSE: IBM) plans to launch the world’s first fault-tolerant quantum computer, IBM Quantum Starling, by 2029, a major leap from today’s error-prone machines.
As these developments unfold, experts are debating when quantum technology might break Bitcoin’s cryptographic defenses, specifically, its elliptic curve cryptography (ECC) and SHA-256 hashing, which secure wallets and transactions.
In this context, Finbold has gathered expert insights on when quantum computing could threaten Bitcoin.
Craig Gidney
In May 2025, Google quantum researcher Craig Gidney warned that the timeline might be shorter than expected. His findings revealed that breaking RSA encryption may require 20 times fewer quantum resources than previously estimated.
While Bitcoin doesn’t use RSA, it does rely on ECC, which, like RSA, can be broken by Shor’s algorithm.
Although Gidney didn’t directly mention Bitcoin, his research targeted encryption methods that underpin crypto wallets and, in some cases, transactions. He suggested a potential threat window between 2030 and 2035, depending on advancements in error correction.
“I estimate that a 2048-bit RSA integer could be factored in under a week by a quantum computer with fewer than one million noisy qubits,” Gidney wrote.
Adam Black
In contrast, Adam Back, an early Bitcoin adopter and CEO of Blockstream, remains more cautious. In April 2025, he argued that quantum computers likely won’t pose a serious threat for at least two decades.
Still, he acknowledged that future breakthroughs could force holders to migrate their coins to quantum-resistant addresses, including possibly Satoshi Nakamoto’s untouched stash, which could reveal whether the mysterious founder is still alive.
David Carvalho
Meanwhile, in a June 2025 opinion published by Cointelegraph, David Carvalho, CEO of Naoris Protocol, issued a more urgent warning. He claimed that quantum computers could crack Bitcoin within five years unless it quickly upgrades its cryptography.
Carvalho specifically pointed to the emergence of technologies like Microsoft’s Majorana chip as a sign that powerful quantum systems are already on the horizon.
According to him, about 30% of Bitcoin is currently stored in vulnerable addresses, and a single breach could shatter the trust built over the network’s 16-year history.
“A breach would be catastrophic for holders, whose funds would be gone forever, and the ecosystem at large. It would prove that the unbreakable system can be broken. That’s why BlackRock recently acknowledged the threat of quantum to Bitcoin in its updated spot ETF filing. That’s why the time to act is now, before it’s too late,” he said.
Chamath Palihapitiya
Similarly, back in December 2024, as reported by Finbold, billionaire investor Chamath Palihapitiya cautioned that Bitcoin’s SHA-256 encryption might be broken within two to five years due to the pace of quantum progress.
His warning came after Google unveiled its 105-qubit Willow chip, which was viewed as a significant milestone. He estimated that around 8,000 such chips could potentially break Bitcoin’s encryption. While scaling to that level remains a major hurdle, Palihapitiya urged blockchain developers to start reworking hashing algorithms now.
Ultimately, the quantum threat to Bitcoin hinges on creating fault-tolerant quantum computers with millions of qubits, a milestone that’s still years away.
Featured image via Shutterstock
