Predicting 2031: IBM’s Roadmap to Large-Scale Fault-Tolerant Quantum Computing by 2029

In June 2025, IBM made a landmark announcement outlining a clear plan to build the world’s first large-scale fault-tolerant quantum computer by the year 2029. See “IBM’s Roadmap to Large-Scale Fault-Tolerant Quantum Computing (FTQC) by 2029” for more information about this ambitious roadmap. IBM’s proposed machine, code-named “Quantum Starling,” is planned to deliver on the order of 200 logical qubits (i.e. 200 error-corrected, high-fidelity qubits) capable of executing 100 million quantum gate operations in a single run. This would be a colossal leap from today’s prototypes. To achieve it, IBM is shifting from single-chip quantum processors to a modular multi-chip architecture: essentially clustering multiple smaller quantum chips and linking them with high-speed quantum interconnects so they function as one larger processor. Along with this modular hardware, IBM is embracing advanced error-correcting codes (specifically quantum LDPC codes, sometimes called “bicycle” codes) instead of relying solely on conventional surface codes. These codes are much more qubit-efficient. IBM believes that by using modular design plus LDPC error correction, it can “crack the code” of scaling – reaching fault tolerance with tens of thousands of physical qubits rather than millions. Intermediate milestones named in the roadmap (with bird codenames like Loon, Kookaburra, Cockatoo) will incrementally demonstrate the needed tech, culminating in the Starling system by 2028–2029.

The cybersecurity significance of IBM’s 2029 target is hard to overstate. A large-scale, error-corrected quantum computer has long been synonymous with the ability to run Shor’s algorithm and break public-key cryptography like RSA-2048 and ECC. Such a machine was often talked about as being decades away, but IBM’s concrete timeline – together with similar efforts by competitors – shifts that horizon to the early 2030s. In fact, the PostQuantum article points out that just days before IBM’s news, researchers (at Google Quantum AI) published results suggesting RSA-2048 could be cracked with ~1 million qubits in a week, implying a capable quantum computer might arrive by 2030. Likewise, Gartner had begun predicting the weakening of classical encryption by 2029, and NIST has advised migrating to quantum-safe crypto by 2030. Now IBM’s roadmap puts an exclamation point on those forecasts. If IBM can deliver ~200 logical qubits by 2029, it means we’re plausibly only a step or two (perhaps a few thousand logical qubits) away from cracking 2048-bit encryption. For CISOs and tech leaders, this serves as a loud wake-up call: the quantum threat is no longer theoretical or “far future” – it has a target date and a development plan. Organizations should be actively preparing their cryptographic infrastructure for this 2029+ reality, as waiting until the last minute could be too late.

Q-Day Impact: IBM’s aggressive roadmap suggests that the first cryptography-shattering quantum computer could be realized in about five to seven years, lending credence to the view that Q-Day (when quantum machines can break RSA/ECC) is likely to hit in the early 2030s – and perhaps even 2030 itself if all the pieces come together.