An efficient technique for secure transmission of the region of interest in medical images

Abstract

In this paper, we propose three ROI (Region of Interest) selective encryption schemes to achieve secure access for medical images. The security in the region of interest is ensured by using inversion or/and permutation function as cryptographic tools. The three schemes are performed during compression. Only few selected MSBs (Most Significant Bit-Planes) of the ROI’s codeblocks are concerned by the encryption. The first permutation scheme incurs a little loss on compression efficiency. The second scheme, inverts a set of important bit-planes of each ROI codeblock with no compression overhead. The third scheme combines the two schemes performing inversion and permutation of the selected ROI’s MSBs. The size of encrypted bit-stream is not changed. Moreover, the JPEG 2000 codestream resulting from the encryption process remains compliant with the JPEG 2000 format. Decryption is provided of course by our decoder which requires the same function to recover the original medical image.