I understand that there were a lot of discussions on this topic, but I tried to collect my mother's up-to-date information.
Bristlecone(72 qubits), Googles New Quantum Processor
https://ai.googleblog.com/2018/03/a-preview-of-bristlecone-googles-new.htmlIBM(127 qubits) creates largest ever superconducting quantum computer
Plans for 2022
"IBM has said that it hopes to demonstrate a 400-qubit processor next year and to break the 1000-qubit barrier the following year with a chip called Condor"
https://www.newscientist.com/article/2297583-ibm-creates-largest-ever-superconducting-quantum-computer/The calculation of the number of qubits for breaking encryption on elliptic curves was published on
January 25, 2022 in the journal AVS Quantum ScienceScientists from the Sussex Center for Quantum Technology (University of Sussex, UK) and Universal Quantum have calculated the number of physical qubits needed to break the 256-bit encryption of keys in the Bitcoin network using an elliptic curve within an available time frame in which it makes sense.
"It would require approximately 317 × 106 physical qubits to break the encryption within one hour using the surface code and a code cycle time of 1 μs, a reaction time of 10 μs, and physical gate error of 10
−3. To instead break the encryption within one day, it would require only 13 × 106 physical qubits. If the base physical error rate was instead the more optimistic value of 10
−4, 33 × 106 physical qubits would be required to break the encryption in 1 h. This large physical qubit requirement implies that the Bitcoin network will be secure from quantum computing attacks for many years (potentially over a decade). Alternative error correction techniques, in particular those that benefit from a more flexible physical qubit connectivity as often found in trapped ion-based quantum computers, could potentially offer considerable improvements to the requirements, but the lower rate of logical operations must also be factored in. The Bitcoin network could nullify this threat by performing a soft fork onto an encryption method that is quantum secure, but there may be serious scaling concerns associated with the switch. We hope to motivate continued research into end-to-end resource estimation for alternative error correction schemes to the surface code, and to determine how best to make use of the available physical connectivity of different quantum hardware platforms."
https://avs.scitation.org/doi/10.1116/5.0073075