Craig Costello gave this TED Talk on how quantum computers will the modern cryptography that is used in smart phones are everything else.
He says public key cryptography depends on the difficulty of factoring integers, and quantum computers will crack that in 10 to 30 years. This poses a risk today because we have military secrets that are supposed to be kept for longer than that, and our enemies may already be stockpiling intercepted data in the hopes that a quantum computer will decode them some day.
He ended saying, "No matter what technilogical future we live in, our secrets will always be part of our humanity, and that is worth protecting."
Really 30-year military secrets are part of our humanity?
Okay, he is just trying to sell his crypto work. He is a cryptographer working on ideas in search of a practical application. That is not why I am posting this.
To convince the TED audience that existing crypto methods are insecure, he explained that the vulnerability was from some startling XX century physics discoveries, that cryptographers did not account for:
(1) a proton can be in two places at once.
(2) two objects, on opposite sides of the universe, can influence each other instantaneously.
(3) a computer can make use of a calculation in a parallel universe.
When were these discovered? Who got the Nobel prizes for these discoveries?
This is why I am a quantum computing skeptic.
Academic cryptography became irrelevant to the real world in the 1990s when all the major problems got solved. The quantum computing hype neatly aligns with research justifications and government grants.
But my real skepticism is based on the facts that the arguments for quantum computing depend on goofy interpretations of physics are not backed up by experiment.
Yes, one can believe in some standard interpretation of QM, such as textbook/Copenhagen/QBism, and still believe in quantum computing, but then quantum computing just seems like a wild conjecture.
Many physicists firmly believe that quantum computing is just an engineering problem. When they try to convince you, they nearly always rely on one or more of the above three "discoveries".