An Optical Video Cryptosystem with Adaptive Steganography

In this paper, an optical cryptosystem with adaptive steganography is proposed for video sequence encryption and decryption. The optical cryptosystem employs a double random phase encoding algorithm to encrypt and decrypt video sequences. The video signal is first transferred to RGB model and then separated into three channels: red, green, and blue. Each channel is encrypted by two random phase masks generated from session keys. For higher security, an asymmetric method is applied to cipher session keys. The ciphered keys are then embedded into the encrypted video frame by a content-dependent and low distortion data embedding technique. The key delivery is accomplished by hiding ciphered data into the encrypted video frame with a specific hiding sequence generated by the zero-LSB sorting technique. Experimental results show that the adaptive steganography has a better performance than the traditional steganography in the video cryptosystem.