Physical layer encryption for coherent PDM system based on polarization perturbations using a digital optical...

Area of Science:

• Optical Communications
• Information Security
• Physical Layer Security

Background:

• Coherent optical polarization division multiplexing (PDM) systems are vulnerable to eavesdropping.
• Existing encryption methods may lack flexibility or efficiency in optical networks.

Purpose of the Study:

• To propose a security-enhanced physical layer encryption scheme for coherent PDM systems.
• To introduce a flexible and robust encryption mechanism based on polarization manipulation.

Main Methods:

• Introduction of a digital optical polarization scrambler (DOPS) for high-speed rotation of the state of polarization (RSOP).
• Design of four encryption modes using digital polarization device matrices and key parameters.
• Integration of a 5-D chaotic system to enhance security and key space.

Main Results:

• Successful implementation and demonstration in a 32 Gbps PDM-QPSK system.
• Authorized users achieved successful decryption, while eavesdroppers obtained no useful information (BER ~ 0.5).
• The scheme prevents brute-force attacks with an expanded key space of 10^60.

Conclusions:

• The proposed DOPS-based encryption scheme offers superior security and flexibility for coherent optical PDM systems.
• The integration of a chaotic system significantly enhances the system's resilience against attacks.
• This approach provides an effective solution for securing high-speed optical communication networks.