Research On Integrity Protection Of Stream Data Based On Data Hiding

With development of the Internet in high speed, the data exchanging through Internet has been the main way for people to acquire and share information, which has been widely used in areas like military defense, scientific researches, Internet medical and intelligent transportation. However, people’s data is not so secure and reliable. Except the faulty of the Internet itself, people’s data can be tampered without permission by evil attacks. Therefore, protection of the stream data has been becoming a focus problem for the governments and researchers.Data hiding technique can embed the integrity information as the form of secret information into the cover. It can not only protect the integrity of the data, but also reduce the amount of data transmission, which makes it a hot topic that protecting the data integrity based on data hiding. In our practical applications, a large amount of data is needed for integrity authentication and tamper location, such as compressed video stream and batch sequences, so the efficiency and speed is of a vital importance. Therefore, it has significant values both in theory and application.Considering requirements of the practical scientific programs and effects of the cover structure on data hiding method, this dissertation chooses two covers:DNA sequence and compressed video stream. Based on these two covers, the dissertation makes deep research on integrity protection of stream data based on data hiding. The main works and innovations of this dissertation are as follows:1. A fast integrity authentication and tamper location algorithm based on data hiding is proposed. As the long sequence data, fast integrity authentication and tamper location is essential for stream data. The traditional method mainly just computes the hash value of the whole file to check the integrity of the whole file, or for the purpose of tamper location, divide the whole file into blocks and locate the tamper blocks one by one, which is not so efficient. Based on the Merkle Tree, we construct a Merkle Hash Tree with the integrity information of each block, and then design the integrity watermark for embedding on basis of the Merkle Hash Tree. The proposed method is applied to the DNA sequence and compressed video stream. The experiment shows the great efficiency of our method, especially in the situation where the tamper rate is low. Considering large amount of data, we also proposed a two-level Merkle Hash Tree. By the first level Merkle Hash Tree, we can locate a single tamper file, and with the second level Merkle Hash tree,we can further location the tamper blocks of the single file. By applying our method into the batch DNA sequences, the experiment results prove that our method is efficient when the tamper rate is below18%.2. A video steganography algorithm based on the coding stream of Trailing coefficient is proposed. In order to improve the efficiency and speed of integrity authentication and tamper location, for videos it is necessary to embed data direct into the compressed video stream. Unlike DNA sequence, compressed video stream has less redundancy for embedding. Besides, the embedding manner should not destroy the structure of the compressed video for the correct decoding. So it is necessary to design a proper data hiding method. With analysis of three types of covers of coding stream of Trailing coefficient, we propose two methods. In the first method, the information is embedded according the order of covers. Compared our method with Sung’s method, our method can bring about less video distortion. Then based on the first method, we proposed our second method. Combining the STC codes, we embed the integrity information into the covers more evenly to minimize the steganography distortion by designing the modification cost of each cover. The experiment results show that the second method is prior to Sung’s mehod and our first method. Finally we do some more research on the relations between video distortion and accuracy of integrity authentication for further use in practical situation.