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In this study we propose a new approach for selective encryption in the Huffman coding of the Discrete Cosine Transform (DCT) coefficients using the Advanced Encryption Standard (AES). The objective is to partially encrypt the human face in an image or video sequence. This approach is based on the AES stream ciphering using Variable Length Coding (VLC) of the Huffman's vector. The proposed scheme allows the decryption of a specific region of the image and results in a significant reduction in encrypting and decrypting processing time. It also provides a constant bit rate while maintaining the JPEG and MPEG bitstream compliance.

In this paper a novel reversible method for fast and safe image transfer is proposed. The method combines compression, data hiding and partial encryption of images in a single processing step. The proposed approach can embed data into the image according to the message size and partially encrypt the image and the message without changing the original image content. Moreover, during the same process the image is lossless compressed. Nevertheless, the compression rate depends on the upper bound of message size to embed in the image. The main idea is to decompose the original image into two sub-images and to apply various processes to each sub-image in order to gain space and increase the amount of embedded data. The two sub-images are then scrambled and partially encrypted. The most significant characteristic of the proposed method is the utilization of a single procedure to simultaneously perform the compression, the reversible data hiding and the partial encryption rather than using three separate procedures. Our approach reduces then the computational effort and the required computation time. This method is specially suited for medical images where one can associate the patient diagnostic to the concerned medical image for safe transfer purpose.

In this paper we propose an approach for monitoring human activities in an indoor environment using detected and tracked face and selective encryption. The objective is to encrypt partially the human face in a video sequence. This approach is based on AES stream ciphering using VLC (Variable Length Coding) of the Huffman's vector. The proposed scheme allows scalable decryption of a specific region of image and result in a significant reduction in encrypting and decrypting processing time. It also provides a constant bit rate and keep the JPEG and MPEG bitstream compliance.