After yesterday's NSA codebreaking revelations, there's some good news for cryptography. A Toshiba research lab has announced a crucial breakthrough in quantum cryptography, the last truly unbreakable form of encryption, which could pave the way for a new generation of private communications networks.

Quantum cryptography uses the properties of light to create effectively unbreakable encryption. Any attempt to tap in affects the signal and can be instantly detected. The system is already in use in some expensive and high-profile setups, most notably in Geneva's banking sector, but it comes with serious limitations. The laser-based process only works over short distances, and it can only be used to connect two computers at a time.

The new breakthrough, published this week in Nature, offers a way to solve the second problem, connecting as many as 64 computers in a setup they describe as a "quantum access network." The breakthrough comes from an improved photon detector that can handle 1 billion photons per second, allowing it to manage photon streams from more than one computer at once. That lets quantum engineers build networks on a more common hub-and-spoke model, potentially opening the door for more sophisticated quantum-powered networks in the future.