If you’ve got communications that absolutely cannot be intercepted—whether you’re a National Security Agency whistleblower, the president of Mexico, or Coca-Cola—quantum cryptography is the way to go.
It harnesses the bizarro-world properties of quantum physics to ensure that information sent from point A to point B isn’t intercepted. The laws of physics dictate that nobody—not even the NSA—can measure a quantum system without disrupting it.
The problem, as Edward Snowden could probably tell you, is that quantum cryptography is still in its infancy. It only works over relatively short distances, and the required gear—including lasers and a dedicated fiber optic network—is prohibitively expensive, limiting its use to a handful of research labs, corporations and governments.
A new research paper from scientists at Toshiba brings quantum cryptography a baby-step closer to the masses. The paper, published today in Nature, explains how to expand a point-to-point quantum network with only two users into a “quantum access network” with up to 64 users.