An interesting article from Scientific American. Accorfing to the article

A team of researchers in China has unveiled a technique that—theoretically—could crack the most common methods used to ensure digital privacy, using a rudimentary quantum computer.

The technique worked in a small-scale demonstration, the researchers report, but other specialists are sceptical that the procedure could be scaled up to beat ordinary computers at the task. Still, they warn that the paper, posted late last month on the arXiv repository, is a reminder of the vulnerability of online privacy.

Are Quantum Computers about to Break Online Privacy?