Security-enhanced optical nonlinear cryptosystem based on modified Gerchberg-Saxton iterative algorithm

For any optical encryption and decryption systems, security is the major concern. In this paper, security of time varying nonlinear term embedded double random phase encoding (DRPE) scheme is enhanced by using Modified Gerchberg Saxton Iterative Algorithm (MGSIA). The encrypted image of DRPE is given as an amplitude input to MGSIA. This makes the cryptosystem asymmetric and endures the basic attacks such as known-plaintext attack, chosen-plaintext attack, and chosen-cipher text attack. Robustness of this model has been checked with various results.