The Research On Signature And Authentication Of Streamed Data Based On Hash Chain

There are plenty of applications depend on stream data (Video, Audio) transported on the internet. What follows is the security problem. What receiver wanted is not only the fluent effect of Video (or Audio), but also the trustworthy and integrity of the received data. On the other hand, stream data has the property of large volume, unpredictable size and easy to lose, while ordinary digital signature is message oriented, and require the predictability of data. So we can't use the traditional message oriented digital signature on stream data applications.The thesis mainly addresses the security problems of stream data transported through internet. It enables the receiver to authenticate sender, guarantee the integrity of the stream data received, while at the same time transport speed is less interfered,and communication overload is reduced, runtime postpone is minimized, and also authenticate the data received even if it is not complete. According to real-time requirement of stream data and losable characteristic of transportation, the thesis analysis existing stream data signature methods such as star-shaped tree-shaped and Golle chain. Considering the condition of limited resource of receiver, it proposes forward placed hash chain data signature scheme based on Gilbert-Elliot Network channel model and enhanced Golle chain stream data signature method. New scheme uses sender pre-cached stream sequence to replace the old design of Golle chain receiver cached stream sequence so that we can construct more flexible hash signature chain on the sender side and at the same time greatly reduce the resource requirement of receiver and expand receive scope and get rid of the possibility of deny of service attack produced by Golle chain while overall postpone is not increased.Although chain-shaped stream data signature is efficient, but it has high rate of chain break. Once the authentication chain is break, the data received will be dropped because of fail of authentication even if it is received intact. Based on the fact that star-shaped stream signature is immune from chain break and effectiveness of chain-shape, the thesis gives a star-chain stream data signature scheme, without adding signature operation, new scheme divides long sequences into several sub sequences, and assembles them using star-shaped, with the result that the scheme decrease the rate of chain break in evidence, increase the speed of hash chain construction.Finally, the thesis introduced the design and realization of stream data signature.Experiment statistics has proven the scheme proposed here can effectively handle the problems of stream data signature and has high package lose tolerance.