We present a security analysis to the virtual optics (VO)-based cryptosystems, in which several aspects affecting security strength of the algorithm involved in such systems are considered. We start with the evaluation of the computational complexities of virtual-optical-imaging (VOI)-based and virtual-optical-holography (VOH)-based cryptosystems as the security strength of a cryptosystem is relevant to its computational complexity. Furthermore, we assess the key length and key space of both VOI- and VOH-based cryptosystems, respectively, to show their performance. Other cryptographic properties such as confusion and diffusion, nonlinearity, as well as resistant capacity to potential attacks are also explored to illustrate the security of VO-based cryptosystem. Finally the scheme of hardware encryption based on virtual optics is briefly discussed.