Research On Security Of Video Data In The Cloud

Digital video is becoming increasingly popular in social life, while cloud computing is a hottopic in the field of information and communication, and thus storing and sharing encoded videothrough the cloud storage platform has became an inevitable trend. However, cloud platform isconsidered to be unsafe, so we use CP-ABE encryption algorithm to protect the video data in thecloud and achieve access control. But by using CP-ABE encryption algorithm to encrypt the videodata stored in cloud storage platform directly, there are still many problems.Based on this, the thesis firstly proposes an efficient encrypting and access policy updatingmethod for shared encoded videos stored in cloud storage platform. By analyzing the characteristicsof H.264/AVC video streams, the method builds the data dependencies, and then builds critical andnon-critical packets based on the data dependencies. After that, the method uses CP-ABE algorithmto encrypt critical packets and uploads it to cloud storage platform, rather than uploads thenon-critical packets directly. Only encrypting the critical packets can effectively improve theefficiency of encryption. Moreover, the video data owner just needs to retrieve the critical packetsfrom the cloud when re-adjusting the access policy. The experimental results show that this methodcan meet the security requirements and significantly improve the access policy updating efficiency.Secondly, the thesis proposes a layered access policy for3D videos sharing based on cloudstorage. In order to achieve a hierarchical access, the paper puts forward a SCP-ABE encryptionalgorithm. Combined with a one-way hash function, the paper proposes a way to provide users withdifferent levels of video services based on user’s attributes dynamically. Simulation results showthat the proposed access policy can provide different video services for users based on theirattributes, include prohibiting service,2D video service and3D video service. Besides that, theproposed access policy can also satisfy the requirements of assuring the3D video security.Finally, the thesis proposes a video data tracking method. When authorized users leak privatevideos to other unauthorized users, we cannot identify the responsibility of leaking video dataeffectively, because that CP-ABE algorithm belongs to one-to-many encryption method. In thispaper, we add watermark embedding algorithm to the original CP-ABE decryption algorithm,which embeds users’ unique identification information to the video data when authorized usersdecrypting the video data. By this way, when leakage occurs, the method can identify theresponsibility by using the watermark information embedded in the leaked video data. Experiments show that the designed video watermarking algorithm shows better robustness and non-visibility,and can effectively track the video data.