- Google researchers say quantum computers need 20 times fewer qubits to break RSA encryption.
- Bitcoin’s elliptic curve cryptography may be vulnerable sooner than experts initially estimated.
- Google urges faster transition to quantum-safe encryption amid rising security concerns.
Google has raised new concerns about Bitcoin’s security in the quantum computing age. A new research paper suggests that cracking encryption may be far easier than previously believed. The company’s lead quantum scientist, Craig Gidney, shared the findings in a blog post on May 20. He revealed that a 2048-bit RSA key could be broken in less than a week using under one million noisy qubits.
That’s a 20-times drop from the previous estimate made in 2019. At that time, Gidney predicted it would require 20 million qubits. The new results suggest that the timeline for breaking encryption is shorter than the crypto industry had anticipated.
Breakthrough Reduces Resources Needed
Google credited the leap to two major innovations: improved algorithms and more sophisticated error correction methods. Researchers found a faster way to perform modular exponentiation, a crucial part of cryptographic math. At the same time, they improved quantum error correction by tripling the density of logical qubits.
This packaging of operations into tighter spaces increased computational efficiency. They also used a method called “magic state cultivation” to make T-states more reliable. These are important ingredients for complex quantum tasks. These changes helped reduce the space needed for standard quantum operations. This means future quantum machines will do more with fewer physical components.
Bitcoin and RSA Face Similar Risks
Bitcoin uses elliptic curve cryptography, which relies on math similar to RSA. If quantum systems can break RSA faster, Bitcoin may also become vulnerable sooner. The threat remains theoretical, for now. IBM’s strongest quantum chip, Condor, has only 1,121 qubits. Google’s own Sycamore runs on 53 qubits. But the rapid pace of innovation is causing concern.
Project 11, a quantum research group, launched a public challenge to test progress. It offers an $85,000 bounty to anyone who can break simplified Bitcoin encryption using a quantum computer, targeting short encryption keys ranging from 1 to 25 bits. While far smaller than Bitcoin’s 256-bit encryption, these tests aim to track how fast the technology is improving.
Related: New Proposal Aims to Protect Bitcoin from Quantum Attacks
Global Systems Also at Risk
Encryption risks go far beyond crypto wallets. RSA protects global communications, banking systems, and digital signatures. Google warned that malicious actors may already be saving encrypted data today to decrypt in the future. To address this, the company has started using ML-KEM, a post-quantum encryption standard, in Chrome and internal systems.
The U.S National Institute of Standards and Technology released its post-quantum cryptography standards in 2024. It urged the phase-out of vulnerable systems by 2030.
Google’s findings now suggest that the timeline may be too slow. IBM plans a 100,000-qubit quantum computer by 2033. Quantinuum targets a fault-tolerant system by 2029. If those milestones are met, Bitcoin and many other digital systems may need urgent upgrades.
