Effects of using an encrypted image corrupted by noise and occlusion in a security system based on joint transform correlator and Gyrator transform

Abstract

Recently, a novel nonlinear encryption system based on joint transform correlator (JTC) in the Gyrator domain (GD) was proposed. The encryption system uses a fully nonlinear nonzero order JTC and Gyrator transform (GT). The decryption system is based on two successive GTs. The proposed system preserves the good quality of the decrypted image while increases the overall security of the complete process. In this work, we analyse the performance of this security system when the encrypted image is affected by common sources of degradation such as noise or occlusion. We test its robustness against additive and multiplicative noise affecting the encrypted function. We also study the effect of data loss due to partial occlusion of the encrypted information. The performance of the encryption-decryption system in the GD is evaluated using the metric of the root mean square error (RMSE) between the original image and the decrypted image when the encrypted image is corrupted by noise or modified by occlusion.