Quantum computing gives us a way in theory to quickly crack certain types of cryptography. Well-funded startups are working on prototype quantum circuits, as are big guns like Intel, Microsoft, and IBM. Success could render a lot of today’s encryption obsolete. In theory.
Academic and industrial research labs have built basic quantum circuits. If Moore’s Law applies to quantum circuits, they will be the next big thing.
I remain skeptical. Quantum computing seems like perpetual motion machines to me, though I’ve never researched reasons to support my intuition. Researcher Gil Kalai presents an argument based on computational theory and models of noise. He argues that practical computations will lose out to noise effects. I’ll be interested to see more about this.