Many years away. A good guestimate is that you need 1M physical qubits factor numbers fast. Also, there is classical public-key cryptography (i.e. encryption a

Many years away. A good guestimate is that you need 1M physical qubits factor numbers fast. Also, there is classical public-key cryptography (i.e. encryption algorithms that run efficiently on today's classical computers) that is not susceptible to quantum computers. And symmetric cryptography has never been susceptible to quantum computers.