We propose and experimentally demonstrate a novel encryption scheme to enhance the physical layer security in broad-cast passive optical networks (PONs). We exploit, for the first time, a new dimension using non-orthogonality for encryption. Different from the conventional masking of data, the proposed chaotic non-orthogonal matrix (CNOM) can also dynamically scramble the number of subcarriers in an orthogonal frequency division multi-plexing (OFDM) signal while maintaining the same bandwidth to further deceive potential eavesdroppers. By simultaneously using faster-than-Nyquist signaling and redundant precoding, the proposed scheme can achieve the compromise between spectral efficiency (SE) and resilience against system impairments, while increasing the overall key space. We then carry out a proof-of-concept experiment to verify the feasibility of the proposed CNOM-based encryption. Results showed that the transmission performance could be improved in addition to the security enhancement.
Bibliographical note© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Funding: The project was partially supported by a research grant (GRF Project No.
14205820) from the Hong Kong Research Grants Council (Corresponding author: Chun-Kit Chan).
- Chaos encryption
- orthogonal frequency division multiplexing (OFDM)
- passive optical networks (PONs)