Microsoft expects commercially useful quantum computers by 2029 if development continues as planned. That date reflects a company target rather than proof that cryptographic attacks will become possible within three years.
Scientists also use different methods when estimating “Q-Day,” the point when quantum machines could defeat common public-key systems. Hardware quality, error correction, logical qubit numbers and operating speed could change the timeline.
Microsoft’s progress therefore adds pressure for earlier planning, but it does not confirm that Q-Day is close. Its topological approach remains one of several designs competing across the quantum computing sector.
Google, Atom Computing, EeroQ and other research groups are also working on qubit stability and error correction. Progress across several systems could matter more than one company’s chip announcement.