RESUMO
Objects acting as inputs of encrypting optical systems can be regarded as having two independent channels: amplitude and phase. In this context, we can use the term "complex objects" to refer these input objects. In this work we explore the way to perform an undercover operation where one channel (amplitude) is used to depict decoy information to confuse intruders, while the other (phase) operates with the true information. Besides, we use the Gerchberg-Saxton algorithm to transform the amplitude and phase encrypted information into pure phase data, therefore increasing the efficiency of the technique as only a single matrix containing these data needs to be sent. Finally, as an example to show the potential of the method, we combine the separate channels in a multiplexing technique with the Gerchberg-Saxton algorithm to generate an efficient multiuser secure process.