Low photon count based digital holography for quadratic phase cryptography.

Area of Science:

• Optics and photonics
• Information security
• Digital imaging

Background:

• Traditional double random phase encryption systems are vulnerable to attacks.
• Photon-counted imaging (PCI) offers enhanced sensitivity and security potential.
• Digital holography is a powerful tool for wavefront reconstruction.

Purpose of the Study:

• To develop a novel encryption method for two-dimensional scenes in the photon-counted imaging (PCI) regime.
• To enhance the security of encrypted data against known vulnerabilities.
• To validate the proposed method using computer simulations.

Main Methods:

• A quadratic phase encoding system was developed for encryption.
• Position-phase-shifting digital holography was used to record encrypted complex samples under photon-limited conditions.
• Reconstruction of the complex wavefront utilized sparse (undersampled) intensity measurements (interferograms) from two positions.

Main Results:

• Computer simulations demonstrated that photon-limited sparse-encrypted data contains sufficient information for authentication.
• The proposed quadratic phase encoding system effectively secured the two-dimensional scene.
• Security analysis using iterative phase retrieval attacks was successfully performed.

Conclusions:

• The quadratic phase encoding system operating in the PCI regime provides a robust solution for securing encrypted data.
• The method overcomes the vulnerabilities of previous encryption techniques.
• Sparse data acquisition and reconstruction are feasible for secure holographic imaging.