Optical Image Encryption with Simplified Fractional Hartley Transform

In summary, we have proposed a new method for image encryption on the basis of SFRHT. Other than the ever-known encryption methods, we have found another useful image encryption technique. This method has the virtues of both FRFT and HT. As a special form for FRHT, SFRHT can add fractional orders in encryption and consequently strengthens the information security to some extent. In addition, being a real transform like HT, it is more convenient and efficient in practical applications since coherent light can be used in this method and the amount of required storage is saved additionally. Some simulation results are also carried out to prove its reliability of this method.