Log — Reality assessments
What can quantum computers actually do?
Every assessment separates theory, laboratory demonstration, hardware demonstration, practical capability, roadmap claims, and disputes — each with a date, a source, a scale, and the hardware it applies to. No scores, no blending.
All assessments10 topics
5 classified assessments · sourcedDoes quantum computing break AES encryption?No. Grover's algorithm (1996) halves the effective key length in theory — AES-128 to about 64 bits, AES-256 to about 128 bits — but its search iterations must run one aft6 classified assessments · sourcedCan quantum computers crack Bitcoin?No — not today, and nothing close to the required machine exists as of 2026. The real long-term threat is Shor's algorithm against Bitcoin's ECDSA signatures, which would5 classified assessments · sourcedWill quantum computers revolutionize drug discovery?Not yet, and "revolutionize" oversells it. As of August 2026, real quantum hardware has simulated only molecules of a few atoms — calculations any laptop does exactly in 5 classified assessments · sourcedHow close are fault-tolerant quantum computers?The core physics milestone has been passed but the engineering has not: error correction that improves as you add qubits was demonstrated on real hardware in December 2024 classified assessments · sourcedDoes quantum computing speed up machine learning?For machine learning on ordinary classical data: no. As of August 2026 there is no demonstrated quantum speedup for any practical ML task, and the headline exponential cl4 classified assessments · sourcedCan quantum computers solve optimization problems faster?Not today, and for most problems possibly never in a way that matters. As of August 2026 there is no demonstrated quantum speedup on any real-world optimization workload:4 classified assessments · sourcedCan quantum computers fold proteins?No. As of August 2026, quantum hardware has "folded" only toy lattice peptides of about 6–10 amino acids — puzzles a laptop solves exactly by enumeration — while classica5 classified assessments · sourcedHas quantum advantage been achieved?Yes, narrowly: quantum computers have beaten the best known classical methods on contrived benchmark tasks, most credibly Google's verifiable Quantum Echoes result (Octob6 classified assessments · sourcedCan quantum computers break RSA-2048?No. As of 2026, no quantum computer has factored anything larger than toy numbers like 15 and 21, and breaking RSA-2048 would take roughly a million physical qubits runni5 classified assessments · sourcedCan quantum computers predict the weather?No. As of August 2026 no quantum computer has ever run a weather forecast, and there is no evidence that current or near-term quantum hardware would help. The relevant al