Quantum Computing and Verifiable Knowledge

Another little piece of the puzzle, how will quantum computing be fundamentally be different than the computing we have known for so long?

Quantum Information Theory

Computer Scientists Expand the Frontier of Verifiable Knowledge
The universe of problems that a computer can check has grown. The researchers’ secret ingredient? Quantum entanglement.

By Kevin Hartnett    Senior Writer   for Quanta Magazine

Imagine someone came along and told you that they had an oracle, and that this oracle could reveal the deep secrets of the universe. While you might be intrigued, you’d have a hard time trusting it. You’d want some way to verify that what the oracle told you was true.

This is the crux of one of the central problems in computer science. Some problems are too hard to solve in any reasonable amount of time. But their solutions are easy to check. Given that, computer scientists want to know: How complicated can a problem be while still having a solution that can be verified?

Turns out, the answer is: Almost unimaginably complicated.

In a paper released in April, two computer scientists dramatically increased the number of problems that fall into the hard-to-solve-but-easy-to-verify category. They describe a method that makes it possible to check answers to problems of almost incomprehensible complexity. “It seems insane,” said Thomas Vidick, a computer scientist at the California Institute of Technology who wasn’t involved in the new work.

The research applies to quantum computers — computers that perform calculations according to the nonintuitive rules of quantum mechanics. Quantum computers barely exist now but have the potential to revolutionize computing in the future.

The new work essentially gives us leverage over that powerful oracle. Even if the oracle promises to tell you answers to problems that are far beyond your own ability to solve, there’s still a way to ensure the oracle is telling the truth. .... "