Based On The Research Of Windows Encryption Image Security Transmission And Implementation

With the rapid development of the network, image data plays an increasinglyimportant role in our daily lives. However, the bandwidth resources are so limited that itis pretty difficult to transmit large amount of image data at a high speed. So image datacompression is necessarily introduced into data transmission. Plus, to avoid attacks fromthe rampant hackers, it is necessary to encrypt the data. Therefore, it is of a large marketvalue to research on a secure encrypted image transmission system.Focusing on the above problem, this thesis studies domestic and foreign image datacompression and encryption algorithms, based on which, the DCT transform, Huffmantransform, the generation of S-boxes, row transform, column transform and mixedcolumn transformation are studied deeply.First of all, the technologies image compression and decompression on BMP filesare studied. To hide the information redundancy which cannot be sensed by naked eyes,we use DCT transformation to get rid of the redundancy, through which, the image databecomes more compact and the network bandwidth resources are saved in a great extent.For naked eyes.Then, the AES encryption and decryption technologies are studied. In theencryption stage, nine S-box query row transformations, the data line transformation,column transform, an S-box query line transformation and expansion of dense keydifferences or are operated. By layers of replacements and loop operations, the data aresecure from the non-authorized.Next, the data transmission technologies are studied, like the establishment of thesockets at the client and server, the communication channel between the client and theserver, the send and receive of the data, and the close of the sockets.In the end, we test the secure encrypted image transmission system and the resultshows that image data can be securely transmitted with a high speed in this system.