Color Image Encryption and Decryption by Using Optical Scanning Cryptography Method

Abstract

AbstractIn this paper, a computer simulation of optical encryption for color images are presented based on the optical scanning cryptography technique that T.C. Poon suggested in 2003. This method is based on using an encryption key; the color image is optically encrypted. The output is a signal at a radio frequency which it transmits to a receiver (secure site) via an antenna for digital storage and decryption. To create an electrical signal, the same optical scanning system is employed in the secure site, along with a decryption key. After that, the electrical signal is analyzed and transferred to a computer for decryption; a digital decryption unit performs a decryption algorithm. The electrical signal is then analyzed and delivered to a computer for decryption, where a decryption procedure is performed by a digital decryption unit. The decryption unit will decrypt the color image if the encryption and decryption keys are identical. To ensure the system’s effectiveness, by applying several image quality measures to measure the quality of the recovered image (after encryption). The encryption result indicates that the proposed technique produces a noise-like structure that reveals no useful information about the original image.KeywordsOptical encryptionOptical scanning cryptographyColor image encryption