A Nobel Prize-winning physicist who helped build Google’s quantum computers warned that Bitcoin may be among the first targets of this technology in the real world.
In an interview with CoinDesk, John M. Martinis said that recent research from Google showing how a quantum computer could break bitcoin encryption in minutes should be taken seriously.
“I think it’s a very well-written article. It shows where we are now,” Martinis said, referring to Google’s latest work on quantum threats to cryptography. “It’s not something that has zero probability; people have to deal with this.”
READ: A simple explanation of what quantum computing really is and why it’s scary for bitcoin
The Google paper describes how a sufficiently advanced quantum computer could derive a bitcoin private key from its public key, potentially in a matter of minutes, dramatically lowering the computational barrier that currently protects the network, Martinis noted, adding that this is one of the issues that needs to be taken more seriously.
READ: This is what it really means to ‘crack’ bitcoins in 9 minutes using quantum computers
While the idea of quantum computers breaking encryption is often presented as distant or theoretical, Martinis said one of the first practical applications may be much more immediate.
The low hanging fruit for quantum computers
“It turns out that cracking cryptography is one of the easiest applications of quantum computing, because it’s so numerical,” he said. “These are the smallest and simplest algorithms. The lowest hanging fruit.”
That puts Bitcoin, which is based on elliptic curve cryptography, squarely in the line of fire, Martinis suggested, confirming what the Google paper warns.
Unlike traditional financial systems, which can migrate to quantum-resistant encryption standards, bitcoin faces a more complex challenge. Its decentralized structure and historic design make updates slower and more contentious, the Nobel Prize winner said.
“Quantum-resistant codes can be used” in banking and other systems, Martinis said. “Bitcoin is a little different, so people should think about this right now.”
The concern centers on a specific window of vulnerability. When a bitcoin transaction is transmitted, its public key becomes visible before it is confirmed on-chain, Martinis explained. In theory, a powerful quantum computer could use that window to derive the corresponding private key and redirect the funds before final settlement, he noted.
However, Martinis cautioned against assuming the threat is imminent. Building a quantum computer capable of executing such an attack remains one of the most difficult engineering challenges in modern science.
“I think building a quantum computer is going to be harder than people think,” he said, pointing to major hurdles around scaling, reliability and error correction.
There is no reason for inaction
Estimates for when cryptographically relevant quantum machines might emerge vary widely. Martinis suggested a period of approximately five to ten years, but cautioned that uncertainty is no reason not to act.
“Given the serious consequences, you have to face it. You have time, but you have to work on it,” he said.
The warning highlights a growing shift within the quantum research community, where scientists are increasingly pointing out risks to existing cryptographic systems while hiding sensitive technical details, a strategy borrowed from traditional cybersecurity disclosure practices.
For bitcoin developers and investors alike, the message is increasingly difficult to ignore.
“The crypto community has to plan for this,” Martinis said. “It’s a serious problem that needs to be addressed.”
Martinis is a 2025 Nobel Prize-winning physicist recognized for his work on macroscopic quantum phenomena and widely known for leading Google’s quantum hardware program, including the 2019 “quantum supremacy” experiment. He is currently CTO and co-founder of Qolab, a hardware company developing utility-scale superconducting quantum computers.
