Encryption at the speed of 100 Gbps

According to a Lightreading report, Telcordia is trying to bring optical security at 100 Gbps using Photonic Layer Security (PLS). PLS changes an optical signals' phase by different amounts at different points, and then applying a similar iteration on a combined optical signal.

That mixes things up, but the number of phase changes involved is small enough to be cracked by trying enough possible permutations. (There's a limit to the number of usable codes that can be applied to that step.) So, PLS calls for multiple signals to get combined, with a second encoding iteration done on the aggregated stream, again using phase shifts. The decoding can be done only with the PLS key.

For details on PLS, please refer to the Journal of Optical Networking (JON) article available here.