This article will describe an optical encryption technical of images which it is proposed in an analogical and digital way. The development of the technical to a digital level, it is made to implementing algorithms (routines) in MATLAB. We will propose a functional diagram to the described analogical development from which designated the optical systems associated with each functional block. Level of security that the jigsaw algorithms provide applied on an image, which has been decomposed into its bit-planes, is significantly better if they are applied on an image that has not been previously decomposed.