Two Israeli university professors and a PhD candidate have created a concept for “stealthy fiber optic communications.” 

Developed by Ben Gurion University of the Negev’s Prof. Dan Sadot and Prof. Ze’ev Zalevsky of Bar Ilan University together with PhD student Tomer Yeminy, the new encryption method enables stealthy transmission of any optical communications signal. 

Currently in the patenting process, the new encryption method spreads the transmission below the noise level in both time and frequency domains.

Because it uses sampling accompanied by temporal and spectral phase encryption, an eavesdropper trying to detect the transmitted signal catches only noise, since the signal is hidden below the noise level. 

“It is analogous to many soft sounds of a lovely symphony scattered through a recording of background noise,” said the researchers. “The authorized user who knows the spreading key is the only one able to detect and enjoy the symphony without the noisy background.

“It should be noted that analysis shows that it will take [an exponential number of] years for an eavesdropper to break the encryption key – which means that eavesdropping is very hard,” they added.

“This method could also be useful in improving the immunity of the fiber optic communications system to jamming,” the researchers pointed out.