Design of reconfigurable and structured spiral phase mask for optical security system

We propose the design and use of structured spiral phase mask as keys in optical security systems. A protocol for the generation of this deterministic and reconfigurable phase mask is demonstrated. Experimental results of the proposed phase masks employed in the double random phase encoding (DRPE) system is presented. To show the advantages of this structured phase mask (SPM) over the random phase mask (RPM), both the encryption and decryption behaviors of the SPM and RPM are compared.