[MMaschin]

If a true quantum computer exists, all encryption algorithms are worthless. Encryption relies on the inherent difficulty In factoring large numbers. That difficulty goes away with the quantum computing.

To factor a large number with a classical computer, requires massive amounts of computing power, for a quantum computer, it would, theoretically be instantaneous.

[RoosterRedux]

So? What's your point?

Encryptions will be selected with quantum algorithms.

[RoosterRedux]

I write algorithms for my own purposes re: the stock market.

They don't amount to much but they eliminate the predictive value of Bollinger Bands and the like.

I have a fast computer but it still takes a couple of hours to finished the routine.

It should be quicker.

[FredZarguna]

Not quite.

Public key encryption becomes useless. But there are still some encryption methods (one-time pads are the best and most straightforward example) that even in theory cannot be broken.

https://en.wikipedia.org/wiki/One-time_pad