Hybrid Physical and Algorithmic Codesign for Information Encryption via Multiplexed Meta-Holography.

Area of Science:

• Optics and Photonics
• Information Security
• Applied Electromagnetics

Background:

• Metasurfaces (MS) offer a new paradigm for information encryption by utilizing multidimensional degrees of freedom (DoF) of electromagnetic (EM) waves.
• Existing MS encryption methods can be further enhanced by integrating algorithmic-layer cryptographic processing.

Purpose of the Study:

• To develop a novel metasurface-based image encryption system.
• To integrate multidimensional EM modulation with algorithmic encryption for enhanced security.
• To demonstrate a hybrid encryption strategy for secure imaging systems.

Main Methods:

• A multifunctional metasurface (MS) was designed to act as a physical key.
• An autoencoder (AE) was used to retrieve phase distributions for configuring the MS.
• Multiplexed holographic channels were created across orbital angular momentum (OAM) modes, polarization states, and frequencies.
• Image data were mapped and encrypted using a Feistel network and Base64 transformation.
• Encrypted data were packaged into a QR code for transmission.

Main Results:

• The proposed framework successfully integrates multidimensional EM modulation with algorithmic encryption.
• The system leverages the MS as a physical key and an AE for phase retrieval.
• The hybrid encryption ensures that the correct image can only be recovered with knowledge of both hardware and algorithmic keys.
• The encrypted data, packaged in a QR code, enable secure transmission.

Conclusions:

• The developed hybrid encryption strategy provides a feasible pathway for versatile encrypted imaging.
• This approach significantly enhances information security by combining physical and algorithmic layers.
• The system has the potential to meet emerging requirements for secure information exchange.