A Study of Batch Image Encryption

• Main Authors: Chang-Sian Wu, 巫昌憲
• Other Authors: Tzung-Her Chen
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/93711550800291119496

碩士 === 國立嘉義大學 === 資訊工程學系研究所 === 95 === As the network bandwidth has gained much more growth, it’s nowadays popular to share a large number of still images via the Internet by means batch transmission. This trend carries out people’s desire for enjoying online multimedia services. In order to keep the confidentiality of traveling images, traditional encryption techniques seem to be well designed to meet this requirement. However, it’s well-known that the size of image is generally much larger than that of text. Furthermore, partial distortion of images is allowed by human visual systems. Hence, traditional cryptographic encryption algorithms are sometimes not suitable for being used directly to encrypt a batch of images. On the other hand, most of the existing schemes aimed at encrypting a single image so that the schemes can potentially be improved to encrypt a batch of images at once in an efficient way. In this thesis, four novel batch image encryption algorithms based on either Visual Cryptography (VC) or Vector Quantization (VQ) are presented to benefit from their computational efficiency and low transmission bandwidth without damaging the original compression rate. The experimental results show the performance in terms of compression rate and extra encryption computational cost.