"Quantum computers do not even exist: all constructions you might read about on the internet today are either prototypes not capable of doing any computation larger than 4 bits, or are not real quantum computers, in the sense that while they may have quantum parts in them, they cannot run actually-meaningful computations like Shor's algorithm or Grover's algorithm. Recently, there have been signs that "real" quantum computers are no longer that far away. However, even if "real" quantum computers come soon, the day when regular people have quantum computers on their laptops or phones may well be decades after the day when powerful institutions get one that can crack elliptic curve cryptography."