Abstract: Various embodiments of a system and method for backing up a plurality of copies of a file are described. A first copy of the file may be owned by a first user, and a second copy of the file may be owned by a second user. The file is split into a plurality of segments, and each segment is encrypted with a respective segment key. Each encrypted segment is transmitted to and stored on a server computer system. De-duplication techniques are used to ensure that only a single instance of each encrypted segment is stored. The segment keys used to encrypt the file segments are also stored on the server computer system in an encrypted form. De-duplication techniques may be utilized so that only a single instance of the encrypted segment keys is stored.

Abstract: One or more computer systems, a carrier medium, and a method are provided for backing up data using a backup server. The user may instruct backup software on a backup server to identify a second computer system (other than the backup server) as the parent computer system of the backed-up files. The backup software may receive the name of this second computer system as input, and the backup software may then output the name to a catalog during the backup process. When the backed-up data is restored, the catalog may be used to identify the parent of the backed-up data as the second computer system. In one embodiment, the data to be backed up may be part of a mirror which comprises substantially the same data as an original data volume. A carrier medium may include program instructions which, when executed, cause the above operations on one or more computer systems.