How powerful does a quantum computer need to become to break Bitcoin's elliptic curve public key cryptography? Quote from a 2022 research paper:

"It would require 317 × 10^6 physical qubits to break the encryption within one hour using the surface code, a code cycle time of 1 μs, a reaction time of 10 μs, and a physical gate error of 10^(−3).

To instead break the encryption within one day, it would require 13 × 10^6 physical qubits"

Today's most powerful quantum computer is at 127 qbits (created by IBM).