Quantum computers are edging closer to being able to break modern security systems. According to the latest research from Google, led by Craig Gidney, a quantum computer with fewer than one million qubits could break 2048-bit RSA encryption, a security standard widely used across the internet, in less than a week. That is a sharp drop from earlier estimates, which put the requirement at roughly 20 million qubits.
A quantum computer with a million qubits is still a future goal, but the pace of progress in the field means the shift to quantum-resistant security is no longer a distant concern. The research provides a blueprint for a future attack and serves as a call for the global security community to prepare for a post-quantum world.
Still, Google told The Verge that its current Willow quantum chip is still "not capable of breaking modern encryption methods," according to Charina Chou, head of Google's Quantum AI. In other words, despite the significant advances, quantum technology still needs time to reach the point where it would genuinely threaten global encryption systems.
A Quantum Breakthrough and What It Means for Security
The new estimate for breaking RSA encryption is the result of progress in both quantum algorithms and error correction methods. Ever since Peter Shor discovered in 1994 that quantum computers could factor large numbers far more efficiently than classical computers, scientists have been working to pin down exactly how much quantum hardware it would take to compromise real-world encryption.
Gidney's latest work builds on recent algorithmic advances, such as the use of "approximate modular exponentiation," which significantly reduces the number of logical qubits required. The research also incorporates a denser error-corrected qubit storage model, drawing on techniques such as "yoked surface codes" and "magic state cultivation" to cut the physical resources needed.
Despite these improvements, the hardware described in the research remains far beyond what exists today. Current quantum computers operate with only a few hundred or a few thousand qubits, a long way from the million-qubit mark. For example, IBM's Condor and Google's Sycamore, with 1.121 and 53 qubits respectively, show where quantum computing stands today.
By the estimate, this hypothetical machine would need to run continuously for five days, maintain an extremely low error rate, and coordinate billions of logical operations without interruption. Google's Charina Chou also stressed: "The estimate suggests we need at least 10 more years and about 4 million physical qubits to be able to break RSA."
The Roadmap Ahead and Post-Quantum Solutions
Although that level of performance is not feasible today, major quantum hardware companies have laid out plans to reach this scale within the next decade. IBM aims to build a 100.000-qubit quantum computer by 2033, in partnership with the University of Tokyo and the University of Chicago. Quantinuum, another example, has announced a goal of delivering a universal, fully fault-tolerant quantum computer by the end of the 2020s, specifically targeting 2029 for its Apollo system.
The security implications are significant. RSA and similar cryptographic systems underpin much of the world's secure communication, from banking to digital signatures. The research findings reinforce the urgency of moving to post-quantum encryption (Post-quantum Cryptography), a set of new standards designed to withstand attacks from quantum computers.
Last year, the US National Institute of Standards and Technology (NIST) released PQC algorithms and recommended phasing out vulnerable systems after 2030. In August, NIST announced 3 finalized algorithms and expects to select 1 or 2 more this year.
Gidney's research does not show that a quantum computer capable of breaking RSA encryption is about to appear. Instead, it underscores the importance of proactive planning. The research gives hardware designers and policymakers a more realistic target, narrowing the gap between theoretical attacks and real-world threats.
Bottom line: Although quantum computers are advancing quickly, they are still not powerful enough to break modern encryption systems. However, the new Google research suggests that day could arrive sooner than expected, with an estimated need of fewer than one million qubits to break 2048-bit RSA encryption in less than a week. That underscores the importance of moving to post-quantum encryption solutions over the next decade, before quantum computers reach the point where they could threaten global security infrastructure. Organizations and businesses should start planning for this transition now, even though Google confirms that its current Willow quantum chip is still not capable of doing this.
