A Hierarchical Selective Encryption Technique in a Scalable Image Codec

International audienceModern still image codecs furnish more than just good distortion-rate performances. They must also provide some services. Scalability in resolution and quality, er- ror resilience and embedded bitstreams were among the first one to be available. There is still room for enhance- ment, especially when it comes to security-oriented fea- tures. Image encryption is one of the aspect of image security. This paper presents the embedding of an encryptionservice in a multiresolution lossless codec. Partial encryption is performed using ciphering only the keystone part of the codec algorithm, a quadtree decomposition. This results in a hierarchical encryption scheme, showing to be a good tradeoff between encryption speed, selective access and robustness