A Million Qubits Needed To Crack RSA Encryption, Says New AIQLAB Report

According to estimates from 2025, breaking a commonly used RSA key would require a machine with on the order of a million qubits. The report explains that while NISQ (Noisy Intermediate-Scale Quantum) computers, ranging from a few hundred to a few thousand qubits, are limited by “noise” and short calculation windows, combining multiple physical qubits into one logical qubit is essential for error correction.

This means current machines do not pose an immediate threat, but achieving truly secure quantum computing requires significant hurdles to be overcome. The vulnerability stems from the potential for a quantum computer to rapidly factor large numbers, a task that underpins the security of RSA, developed in 1977 by Rivest, Shamir and Adleman.

NISQ Era Limitations and the Threshold of Quantum Threat

This calculation, detailed in a recent report, indicates that current quantum computers pose no immediate danger, but achieving truly secure quantum computing presents a substantial hurdle. John Preskill coined the term “NISQ (Noisy Intermediate-Scale Quantum)” in 2018 to describe the current era of quantum computing, highlighting that these machines are limited by “noise” and can only perform short calculations before errors occur. This means the number of usable, stable qubits is far lower than the total qubit count, extending the timeline for a viable cryptographic threat. “Pomnożenie dwóch dużych liczb pierwszych jest łatwe, ale odgadnięcie, z jakich liczb pierwszych powstał wynik, jest przy odpowiednio dużych liczbach praktycznie niemożliwe,” the report states, outlining the mathematical foundation of RSA security. The potential for “Harvest Now, Decrypt Later” attacks, collecting encrypted data for decryption when quantum computers mature, is a particularly pressing concern.