Three-fold information encryption based on polarization- and wavelength-multiplexed metasurfaces

Area of Science:

• Optics and Photonics
• Materials Science
• Information Security

Background:

• Metasurfaces enable multi-image integration for optical encryption.
• Existing methods often rely solely on polarization, posing security risks.
• Need for more complex and secure encryption strategies in optical information storage.

Purpose of the Study:

• To propose a three-fold information encryption strategy using a dielectric metasurface.
• To integrate a color and two grayscale images on a single metasurface platform.
• To enhance optical encryption security beyond polarization-only keys.

Main Methods:

• Designing dielectric metasurfaces with customized nanobricks.
• Utilizing polarization-mediated transmission characteristics at specific wavelengths.
• Implementing a multi-key encryption system combining polarization and wavelength.

Main Results:

• Successfully integrated a color and two grayscale images on one metasurface.
• Demonstrated polarization and wavelength as distinct encryption keys with varying complexity.
• Prevented decryption using additional analyzers, enhancing security against conventional attacks.
• Generated false information under non-designed illumination conditions.

Conclusions:

• The proposed dielectric metasurface offers a secure and versatile platform for multi-channel optical information encryption.
• The three-fold encryption strategy significantly reduces the risk of unauthorized access compared to polarization-only methods.
• This approach provides an easy-to-design and difficult-to-disguise scheme for advanced optical security applications.