A New Secure Digital Camera Model Based on State Parameter

The current secure digital camera (SDC) model can not identify the secondary capture image and have to validate the integrity of watermarked images taken by it. To address these problems, a state parameter based SDC model is proposed by generating and transferring secret key which is used to produce a watermarked image. The cascade chaotic mapping is used to generate the camera key for the proposed SDC model. By the application of the plaintext data including camera key and state parameters in the image creation, such as viewfinder mode, focus, and time, the secret key is produced by Hash function. The confidentiality and anti-counterfeiting of secret key for the proposed SDC model were validated and one to many nonlinear mapping between the camera and the secret key was established. Experimental results demonstrate that the bit number variation of secret key follows approximately uniform distribution when the camera key or scene parameter is changed.