A new selective encryption technique of JPEG2000 codestream for medical images transmission

In this paper, a novel selective encryption image scheme based on JPEG2000 is proposed, which encrypts only the code-blocks corresponding to some sensitive precincts. In order to improve the security level we introduce the permutation of codeblocks contributing in the selected precincts. Symmetric encryption AES with CFB mode is used to encrypt swapped codeblocks. The idea of combining permutation and selective encryption is used in order to minimize the amount of processed data encryption while ensuring the best possible degradation through the permutation. The proposed process encryption doesn´t introduce superfluous JPEG2000 markers in the protected codestream, i.e, the protected codestream format is compliant to JPEG2000 codestream one. It keeps file format and compression ratio unchanged and doesn´t degrade the original error robustness. The proposed scheme works with any standard ciphers and introduces negligible computational cost.