Quantum Breakthrough in Encryption Security Reduces Qubit Count to 100,000 for RSA Cracking

Breaking encryption with a quantum computer has become significantly more feasible, according to recent research, though experts caution that practical implementation remains years away. A study published in 2026 by researchers at Iceberg Quantum in Australia and colleagues has reduced the estimated number of qubits required to crack RSA encryption from millions to approximately 100,000.

This development, detailed in a preprint on arXiv (DOI: 10.48550/arXiv.2602.11457), leverages a novel qubit connectivity scheme called qLDPC code, which allows qubits to interact over greater distances rather than being limited to nearest-neighbor interactions. This advancement could theoretically enable quantum computers to break 2048-bit RSA encryption in a month with 98,000 superconducting qubits, or in a day with 471,000 qubits, according to the study.

The RSA algorithm, a cornerstone of modern cryptography, relies on the computational difficulty of factoring large prime numbers. Since the 1990s, researchers have known that quantum computers could theoretically sidestep this challenge using Shor’s algorithm, but the required qubit count was prohibitively high. Previous estimates, such as those by Google’s Craig Gidney in 2025, reduced the threshold to under a million qubits.

Iceberg Quantum‘s work further slashes this number, though experts like Scott Aaronson of the University of Texas at Austin have expressed skepticism about the practicality of implementing such a scheme. Aaronson notes that connecting distant qubits remains a significant engineering hurdle, as highlighted in a blog post by Gidney.

Google‘s blog post from February 2026 underscores the urgency of preparing for a quantum-safe future. The company acknowledges that quantum computers could eventually break current encryption standards but emphasizes that no large-scale quantum computer (CRQC) capable of doing so exists yet. Google has been working since 2016 to transition to post-quantum cryptography (PQC), aligning with NIST guidelines.

The firm’s Quantum AI team has championed qLDPC codes, which are seen as critical for scaling quantum hardware. However, IBM, which has also adopted qLDPC codes, notes that these approaches may not be feasible for all quantum computing architectures, particularly those using cold atoms or ions, which operate more slowly.

RSA Security, in a blog post from October 2024, disputes claims that quantum computing poses an imminent threat. The company clarifies that factoring a 50-bit integer—used in the recent study—is vastly simpler than breaking 2048-bit RSA encryption, which requires exponentially more computational power. RSA argues that current quantum computers, with only 1,000 qubits and limited coherence times, are far from capable of cracking real-world encryption.

The company emphasizes that NIST’s post-quantum cryptography standards, finalized in 2024, provide robust safeguards for the next decade, with 2048-bit RSA keys expected to remain secure until at least 2030.

The implications of these developments are profound. While quantum computing could revolutionize fields like drug discovery and materials science, its impact on cybersecurity remains theoretical. Experts warn that organizations should prioritize immediate threats, such as weak passwords and unpatched software, rather than overhyping quantum risks.

As Lawrence Cohen of Iceberg Quantum notes, the potential for quantum decryption underscores the need for proactive transition to PQC, but the timeline remains uncertain. Governments and private sector entities are urged to collaborate on standardizing PQC and modernizing infrastructure to mitigate future risks.

In summary, while the reduction in qubit requirements for breaking RSA encryption represents a technical milestone, practical quantum decryption remains decades away. The race to develop scalable, error-corrected quantum computers continues, with both theoretical breakthroughs and engineering challenges shaping the trajectory of this field. As the quantum era unfolds, the balance between innovation and security will define its impact on global digital infrastructure.