Summary: | 碩士 === 國立臺灣大學 === 資訊工程學研究所 === 103 === This thesis presents an encrypted graylevel images compression system, where a data sender (DS) or creator, without sufficient storage space and computing
power, wants to transmits the encrypted images to a trusted data receiver (DR), through a untrusted channel run by a service provider (SP) who has to compress the images for saving the transmission bandwidth while the images might be encrypted by DS beforehand.
Most of related works designed a special encryption function which leaked a little information that were useful for compression but rarely told the contents of the original images. However, with the traditional stream cipher, only distributed source coding (DSC) based methods are pplicable. Based on state-of-the-art work and the newest distributed video coding scheme, we realized a real system in which lossless compression of stream cipher encrypted graylevel images can be accomplished with a bit rate lower than other related works. In the end, several future work directions will be mentioned to conclude this work.
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