A review of single and multiple optical image encryption techniques

Abstract

Secure communication is of great importance in the modern world. Many methods, techniques, and systems are used for secure communication, many of which cannot be used in applications due to various reasons. Optical methods have been developed for secure communication in the last 25 years. In this study, optical encryption methods are examined in three sections. In the first section, single image optical encryption techniques are analyzed, while in the second section, multiple-image optical encryption techniques are examined. In the last section, standard test techniques for security are examined. The main single image optical encryption techniques are double random phase encoding (DRPE), DRPE and photon counting, phase truncated Fourier transform-based asymmetric optical encryption, diffractive imaging-based optical encryption, interference-based image encryption, and ghost imaging-based optical encryption. The main techniques of multiple-image optical encryption are wavelength multiplexing-based multiple-image encryption, position multiplexing-based multiple-image encryption, phase retrieval-based multiple-image encryption, 4-f correlation-based image encryption, and compressive sensing-based multiple-image encryption. These methods have been analyzed in detail and their advantages, disadvantages, and MATLAB application codes are given in the .

Triple Color Image Encryption Using Hybrid Digital/Optical Scheme Supported by High-Order Chaos

“…The Optical Encryption (OE) process treats the image directly as a twodimensional (2D) object and therefore, it does not use image digitization as done in the Digital Encryption (DE) counterpart [5] [6]. Further, OE methods have some characteristic features due to the used optical devices [7] [8]. For example, the amplitude and phase information of all image pixels can be processed simultaneously.…”

“…Further, image encryption can be processed in various matrix spaces such as phase and polarization, which offers additional security level and reliability. The general structure of OE schemes consists of lasers, spatial light modulators (SLMs), lenses, beam splitters, and detectors [7] as shown in Fig. 1.…”

Inkjet Printing of Biocompatible Luminescent Organic Crystals for Optical Encryption

“…The rapid growth of the consumer market raises a problem for protecting personal information and goods from counterfeiting, thus forming a new direction in material science and digital technology to encrypt the information. − One of the promising solutions, combining new materials and encryption technologies, is optical information encryption, since it is a quite fast, remote, safe (including for human health), and low-energy-consumptive approach. − In most cases, optically active or photoluminescent inorganic, organic, and hybrid materials − are utilized for optical encryption through a change in their color or photoluminescent (PL) signal. However, the design and fabrication of the optical security marks on arbitrary surfaces with PL decoding, allowing also a human contact, is still in its infancy.…”

Quantum Dots‐Functionalized Encryption Camera for Text Image Security Protection

“…[2] It is very necessary to encrypt the text image for security protection. [3,4] To our knowledge, there are three typical ways to achieve image encryption, including fluorescent material-based encryption, [5][6][7][8] computer cryptology, [9][10][11][12][13] and optical encryption, [14][15][16][17][18][19][20][21] while these techniques hardly satisfy the high-speed encryption requirements of information acquisition and online communication. The information encryption using fluorescent materials is limited to hard copy such as paper-based images.…”

“…[6,22,23] Although computer cryptology is effective to encrypt digital images, the efficiency is easily limited by the computer and algorithm. [9][10][11][12][13] Because most of the optical encryption techniques strongly rely on precision equipment or micro-/nanofabrication techniques, it is very difficult to integrate the setups with mobile devices [15] or fabricate micro-/nanostructures. [16][17][18][19] Therefore, it has been much desired to develop a simple and rapid way to encrypt digital images efficiently.…”