Content Access Control for JPEG Images using CRND Zigzag Scanning and QBP

This paper introduces a combination of two new scrambling techniques to produce both obscured and incomprehensible scrambled JPEG image. The techniques are called Combined-Reverse-and-Normal- Direction (CRND) Zigzag and Quantized Blocks Permutation (QBP) scrambling. The scrambling techniques are easy to be implemented and by combining both techniques, the scrambled image has higher resistance to spatial plain-text attack. The resulting scrambled image is compatible to JPEG decoder standard. Our experimental results shows that the technique incurs tolerable fluctuate bit overhead as compared to the original JPEG without the loss of image quality.