Optical image encryption based on diffractive imaging

TLDR

The authors propose an optical image encryption technique that employs diffractive imaging. Encryption is performed by selecting and laterally translating one of several random phase‑only masks in a multiple‑mask system, while decryption uses a phase‑retrieval algorithm to recover a high‑quality plaintext image. Numerical simulations confirm the method’s feasibility and effectiveness, offering a novel alternative to conventional interference approaches and opening new avenues for optical image encryption research.

Abstract

In this Letter, we propose a method for optical image encryption based on diffractive imaging. An optical multiple random phase mask encoding system is applied, and one of the phase-only masks is selected and laterally translated along a preset direction during the encryption process. For image decryption, a phase retrieval algorithm is proposed to extract a high-quality plaintext. The feasibility and effectiveness of the proposed method are demonstrated by numerical results. The proposed method can provide a new strategy instead of conventional interference methods, and it may open up a new research perspective for optical image encryption.