Google says quantum computers might break Bitcoin way sooner

Google revealed that breaking the RSA encryption, the same tech that secures crypto wallets, might need 20 times fewer quantum resources than previously estimated. The tech company introduced a new quantum computing chip called Willow in December 2024 and said it could break Bitcoin in at least two days.

The firm argued that Willow could solve in five minutes a problem that would take most supercomputers 10 septillion years to solve. At the time, critics believed Willow’s power could overtake Bitcoin’s hash rate in minutes, rewrite the Bitcoin blockchain, or even steal Satoshi’s coins.

Google sees quantum computing as a potential threat to BTC’s security

"2048-bit RSA #encryption could theoretically be broken by a #quantum computer with 1 million noisy qubits running for one week."https://t.co/MoxGROF3Va #PQC #cybersecurity

— Jari Pirhonen (@japi999) May 26, 2025

Google said its breakthrough moved quantum computing one step closer to becoming a practical reality and a potential threat to Bitcoin’s security. The company’s Quantum Researcher, Craig Gidney, believes that planning the transition of quantum-safe cryptosystems requires understanding the cost of quantum attacks on vulnerable ecosystems.

Gidney said he published an estimate in Gidney+Ekera 2019 stating that 2048-bit RSA integers could be factored in eight hours by a quantum computer with 20 million qubits. According to him, he significantly reduced the number of qubits required in his research paper.

“I estimate that a 2048 bit RSA integer could be factored in less than a week by a quantum computer with less than a million noisy qubits. This is a 20-fold decrease in the number of qubits from our previous estimate.”

–Craig Gidney, Quantum Research Scientist at Google.

Google’s researcher believes that people’s digital assets are still safe for now. He also argued that the trajectory is what matters, and it’s pointing in a direction that should make anyone holding crypto pay attention.

Google said the breakthrough would come from better algorithms and smarter error correction. On the algorithmic side, the firm’s researchers figured out how to calculate modular exponentiations twice as fast as the heavy mathematical lifting in encryption. The team also found that error correction improvements were possible because they tripled the density of the logical qubits’ space by adding a new layer of error correction, which packaged more useful quantum operations into the same physical space.

Google researchers also deployed magic state cultivation – a trick that makes special quantum ingredients (called T states) stronger and more reliable. The team said it helps quantum computers perform complex tasks more efficiently without wasting extra resources, which reduces the workspace needed for basic quantum operations.

Bitcoin operates on elliptic curve cryptography, which works on mathematical principles similar to those of RSA. Google believes that if quantum computers can crack RSA faster than expected, BTC’s security timeline just got smaller.

Project 11 believes quantum computers running Shor’s algorithms might break BTC

We just launched the Q-Day Prize.

1 BTC to the first team to break a toy version of Bitcoin’s cryptography using a quantum computer.

Deadline: April 5, 2026
Mission: Protect 6M BTC (over $500B)

— Project 11 (@qdayclock) April 16, 2025

A quantum computing research group called Project 11 launched a Bitcoin bounty worth nearly $85,000 for anyone who can break even a simplified version of BTC’s encryption using a quantum computer. The team is testing keys ranging from 1 to 25 bits, smaller compared to Bitcoin’s 256-bit encryption, but it entails tracking progress.

Project 11 wrote that BTC security relies on elliptic curve cryptography. The research group also believes that quantum computers running Shor’s algorithm will eventually break it. The team is now testing how urgent the threat is.

Google believes competitors could already be collecting encrypted data to decrypt later once quantum computers become available. The tech firm said it has been encrypting traffic both in Chrome and internally, switching to the standardized version of ML-KEM once it became available.

The National Institute of Standards and Technology released post-quantum cryptography standards last year and recommended phasing out vulnerable systems after 2030. Google’s research suggests that the schedule might need to be accelerated.

IBM has partnered with the University of Tokyo and the University of Chicago to plan for a 100,000-qubit quantum computer by 2030. Quantinuum also aims to deliver a fully immune quantum computer by 2029. 

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