Patent attributes
A backup system can be provided, which system can comprise an identifier operable to identify a data object for possible backup and a generator operable to generate an identity representation for the data object on the basis of the content thereof. The identity representation can be transmitted to a backup store where it can be tested against identity representations for previously stored objects. The system can also comprise a receiver operable to receive from the backup store an indication of whether the data object described by the identity representation has previously been stored at the backup store. The system can be operable to transmit the data object to the backup store in the event that the data object described by the identity representation has not previously been stored at the backup store.