preferable to utilize a strong block cipher such as triple des or aes at step 308 the bundle is then tagged with some backup identification information e g the username requesting the backup operation the network address of the user 39 s machine the time and date of the backup etc at step 309 the bundle is then sent over to the untrusted remote backup server it should be noted that due to the nature of how the bundle is constructed the file system structure and the files names are advantageously hidden from the remote server 120 and from anyone listening in on the network 100 the remote backup server 120 waits for communications from a backup client 110 at step 310 when the remote server 120 receives a bundle at step 311 it can store the bundle indexed by the tags at step 313 it is preferable for the remote backup server 120 to provide some user authentication mechanism when a user performs a backup e g as set forth in step 312 in fig3 otherwise although the information on the server is potentially useless to anyone assuming it is properly encrypted there may be nothing preventing another user from corrupting or destroying backups or attackers could fill up the storage areas of the servers with any other material they want users should be strongly advised not to use their backup passphrase.