摘要:More recently, the capability of computational power being dispersed in the cloud is seen as a massive leap forward that allows for improvements in network bandwidth, computational power capacity expansion, and the ability to store data on the cloud. The knowledge is updated and shared more readily on the cloud, which is beneficial for clients. To verify the consistency of shared data blocks, you must compute the authentication signatures on all of each one (client-side)node and each peer- (or all)nodes in the cluster. A distinct block of shared data was registered with a distinct user. The block must be re-signed by the user who still has access to it if it has been withdrawn from the previous signatory (a user previously permitted to sign blocks must still be present if blocks are being reissued to him). However, since files of this size affect cloud performance, there is the risk of bogging down the server while sending and accessing them. If the shared data that the user previously had downloaded has expired, the former client will automatically re-sign at the time of user revocation. Since the current system is less focused on protection and the data backup process, data is vulnerable to lose in a system failure event. It was the first paper to introduce the truth about shared data and the use of AES encryption to secure data against cloud server tampering and suggested the use of a new mechanism to locate it, such as the recovery procedure. Comparison of the two systems revealed far more flaws in the current system, but several additional problems with the new one and another critical aspect of the Group Policy Management feature are key revocation. When a user is kicked out of a group, their personal security credentials (i.e. his or her keystrokes) are revoked, new personal keys are distributed to current users in the group..