I think It will never happen, Not easy to crack bitcoin private with quantum computer.
Until now, I didn't hear about it.
No one can do.
Nevertheless, quantum computers have been created and continue to improve. So, scientists in Austria managed to improve a quantum computer and create the world's first universal quantum computer, which is built on the basis of kudits - the so-called multi-level quantum bits.
The essence of the discovery is that most of the existing quantum computers are computers built on the basis of the so-called qubits - quantum analogues of logical bits (artificial analogues of the hydrogen atom with two energy levels). Along with qubits, there are qudits - more complex quantum memory cells - qutrits and kukvadras - structures with three or four levels. In theory, kutrits and kukvadras allow you to process more data with fewer particles, but at the same time they are much more difficult to manipulate and connect with each other.
Therefore, the researchers decided for the first time to use qudits based on calcium ions - such a move made it possible to create a universal quantum computer that will significantly increase the speed of calculations.
In such a machine, each of the qudits has eight well-defined energy levels, seven of which physicists have learned to use for calculations.
And if you place a calcium ion in a magnetic-electric trap, illuminating it with a laser, you can manipulate the properties of the energy levels.
It was this idea that helped create two prototypes of a universal quantum computer built on the basis of three and ten qudits. Such a computer is capable of performing all the logical operations available to qubit computers by changing the number of energy levels used in individual qudits.
According to Austrian physicists, while the created computers make many random errors during operation, however, in the near future, scientists plan to significantly reduce their number. This, in particular, can be achieved by using more powerful magnets and high-frequency traps to retain calcium ions.
All statements that such computers will be very expensive and will be used only for research do not hold water. Criminals will take them first. After all, if they hack wallets with bitcoins worth several billion dollars, then for them it will be worth it and they will pay any amount for such a computer.