Patent ID: 8874908
Filing Date: 2014-10-28
Classification: G06F,H04L

Abstract:
1. A process for storing data on a central server, a plurality of users of said server each having a user password which is at least used for generating a user key and at least one client with data saved thereon being respectively assigned to at least some of these users and, as required, at least some of these data being subdivided into at least one data block to be uploaded, and, based on a unique data block ID value identifying each data block, it is determined whether a corresponding data block is already present on the server, the data blocks not being present on the server being uploaded to said central server, a data block list to be uploaded being compiled and uploaded to the central server, based on which data can be regenerated in their original form by a data recovery step following a request for data stored on the central server by the user, wherein a file key is generated using a key generation rule which uses an unencrypted file consisting of at least one data block as an integral component for generating said file key; the following steps are carried out for each unencrypted data block on the client, wherein the unencrypted data block is first compressed, in order to determine the data blocks and the data block list to be uploaded to the central server: and wherein the following steps are carried out after having completed the above steps for each unencrypted data block: the unencrypted data blocks, the unencrypted data block list, the unencrypted file key, the unencrypted ID value of the list of data blocks and the user key remaining exclusively on the client; and, in the data recovery step, the server sending the data which are stored on the server in their encrypted form, the server being not able to decrypt them, to the client, so that data recovery is only carried out on the client.