Image scrambling method for information distribution via vector quantization codebook processing

Efficient encryption techniques are essential to multimedia data security for the distribution of digital images, since digital data has huge amount of data and real-time processing is often required. Contents providers hesitate to disclose the original data due to the illegally copied problem, which result in the serious impediment to distribute digital images. This paper provides a method of scrambling image data for confidentiality, which turns image datum into scrambling ciphers by using Vector Quantization Codebook Processing (VQCP) in order to solve this problem. We present analysis results showing that through VQCP composed of the two key techniques to ensure the security, i.e., VQ-index conversion and VQ-pasting location conversion, the security is achieved without sacrificing the image compression performance and the computational speed. Its high-speed transformation enables real-time scrambling/de-scrambling, thereby preventing illegal copying. As a result, it has become possible to scramble afull-color XGA natural image (1024x768 pixels) in less than 2.5 rns, i.e., real-time scrambling of image has become available.