Research And Implementation Of File Backup System Based On Asymmetric Secure Storage

Cloud computing is developing rapidly in recent years,the "cloud storage" has emerged as one of the important branches of cloud computing,which has been regarded as a brand-new storage method and applied wildly,resulting in more and more commercial products.The advantages of development and the problems to be encountered have been summarized by analyzing the commercial products of cloud storage and current domestic and international research status in this thesis,a new model based on file fragmentation storage has been proposed based on the analysis above in this thesis,and a system named backup of file fragmentation based on asymmetric security has been finally designed.The research content of this thesis mainly consists of:1.The technology of breaking and bonding document.This technology proposes a targeted file fragmentation algorithm for existing descriptor-based file recovery technologies,and improves file security by fragmenting file header data and file bodies.The purpose of file fragmentation is to hide file descriptors and corrupt file byte frequency.2.Technology of asymmetric secure storage.A new type of storage based on cloudy hybrid is proposed:the user stores the same file in different public cloud storage servers,and the information such as the index and storage address between the fragments is saved to the local metadata.Users can restore target files easily via metadata,but it is extremely difficult for users who do not have metadata to restore the target files.The security problem for storage of large files could be solved by exploiting technology of asymmetric secure storage,so that achieve certain security for the data of users without being encrypted.At the same time,the technology provides new ideas for improving the security of data on third-party cloud storage devices.3.Dynamic selection technology of cloud storage.The technology aims at improving user experience and reduce system cost by dynamically performing file resource scheduling,which is under the condition that the different factors consist of response speed of cloud service,transmission speed of file,and cost for unit storage space of multiple cloud storage providers are totally different.Moreover,this technique needs to be dynamic so that the scheduling scheme can be adjusted at different times and states.