Patent ID: 7987327

Claim:
A backup system in which a plurality of backup request devices is connected to a backup device, wherein: each backup request device includes: a content data storage section that stores a piece of content data; and a transmission section that regards the piece of content data as a piece of backup target data and transmits to the backup device, along with a piece of device identification information, a piece of backup information that includes a piece of data quality information indicating a data quality of the piece of backup target data and a piece of content identification information, and the backup device includes: a storage section that stores a piece of backup data having a same content as the piece of backup target data and whose data quality is higher than or equal to the piece of backup target data such that the piece of backup data is associated with the piece of content identification information; a receiving section that receives from the backup request device the piece of backup information and the piece of device identification information; and a control section that stores, when the receiving section receives the piece of backup information and the piece of device identification information, the piece of backup information in the storage section such that the piece of backup information is associated with the piece of device identification information.