On compression of encrypted data

Abstract

In this thesis, I took advantage of a model-free compression architecture, where the encoder only makes decision about coding and leaves to the decoder to apply the knowledge of the source for decoding, to attack the problem of compressing encrypted data. Results for compressing different sources encrypted by different class of ciphers are shown and analyzed. Moreover, we generalize the problem from encryption schemes to operations, or data-processing techniques. We try to discover key properties an operation should have, in order to enable good post-operation compression performances.