The Collins Formula Applied in Optical Image Encryption

We propose a novel method for image encryption, which is realized by the Collins formula with the random shifting method. The Collins formula can denote different optical transforms by one expression with different ABCD elements. For a generalized optical system, the ABCD elements can be randomly chosen, so the keys are increased and the security of the system is strengthened. Finally, some computer simulations are given for different encryption systems to prove the possibilities. The encryption effect is good, and people without the correct keys can not obtain the information easily.