Quantum system hacked in 'blinding' attack

Researchers at the Norwegian University of Science and Technology (NTNU) have discovered a way to hack quantum network traffic using currently available technology.

Quantum signals are touted as perfectly secure, since the act of observing the signal changes it and alerts the receiver to the interception.

However, the researchers discovered a way to use a one milliwatt laser to fool the receiver into believing the message has not been tampered with, when in fact it can be harvested using traditional techniques.

"Our hack gave 100 per cent knowledge of the key, with zero disturbance to the system," Vadim Makarov from NTNU told Nature.

"We have exploited a purely technological loophole that turns a quantum cryptographic system into a classical system, without anyone noticing."

'Blinding' the receiving station allowed the team to harvest the data they needed. The attack worked on two commercially available quantum cryptography systems from Swiss firm ID Quantique and a MagiQ Technologies system built in the US.

"Once I had the systems in the lab, it took only about two months to develop a working hack," said Makarov.

The team contacted both companies before publishing its research, and patches have now been issued.

“We provide open systems for researchers to play with and we are glad they are doing it," said Anton Zavriyev, director of research and development at MagiQ.