Systems and methods for encrypting communication over a fiber optic line

Point Optical Link communication security to help resolve the high resource requirements and lack of a trustworthy source of high randomness of existing communication security solutions is described herein. The scheme includes a novel model and a physical layer symmetric cryptographic key generation technique that focuses on exploiting the physical randomness manifested by the Polarization Mode Dispersion effect. This randomness makes it extremely difficult for an adversary to generate the same cryptographic keys as the communicating parties. 128 bit keys with low final mismatch rates (.ltoreq.10%) can be generated, which could easily be truncated for 64-bit and 32-bit keys if necessary.