Predicting 2030: My Updated Q-Day Prediction

Based on all the recent developments I revised my Q-Day prediction and published it here: “Q-Day Revisited – RSA-2048 Broken by 2030: Detailed Analysis.”

In summary, I predict that the Q‑Day, the first practical quantum break of RSA‑2048, will land around 2030 (±2 years). My case rests on three 2025 pivots: (1) Craig Gidney’s result that roughly 1,000–1,400 logical qubits—<1M physical qubits for ≈a week of runtime—could factor RSA‑2048; (2) fidelity gains, from Oxford’s ~10⁻⁷ single‑qubit error rate to Google’s validation that larger surface codes cut errors; and (3) firm roadmaps, notably IBM’s aim for ~200 logical qubits by 2029 with a path to 1,000+ early in the 2030s.

The intersection of shrinking algorithmic needs and scalable hardware shifts Q‑Day from “if” to “when,” earlier than many recent estimates.