Information terminal device and content backup method
A management information generating section generates management information in which the correspondence between content data and rights data is described when a digital DCF container containing encrypted content data and a rights object described in association with a right which decrypt the content data are stored in an external media card. A backup section writes the DCF container, rights object and management information onto the external media card.
1. An information terminal which manages encrypted content data and rights data used for decrypting the encrypted content data, and which is operable to store the encrypted content data and the rights data on an external storage medium, said information terminal comprising:
detecting means for detecting, that an item of encrypted content data and an item of rights data corresponding thereto are to be stored on the external storage medium, and for then detecting one of: (i) that a same encrypted content as the item of encrypted content data to be stored is already stored on the external storage medium, and (ii) that the same encrypted content as the item of encrypted content data to be stored is not already stored on the external storage medium;
generating means for (i) generating, at the information terminal, first management data that includes first identification information identifying the item of encrypted content data and second identification information identifying the corresponding item of rights data, responsive to the detecting means not detecting the same encrypted content on the external storage medium, and (ii) generating, at the information terminal, second management data that includes third identification information identifying the item of encrypted content data already stored on the external storage medium and the second identification information identifying the item of rights data, responsive to the detecting means detecting the same encrypted content on the external storage medium; and
writing means for (i) writing from the information terminal to the external storage medium the generated first management data, the encrypted content data, and the rights data onto the external storage medium, responsive to the detecting means not detecting the same encrypted content on the external storage medium, and (ii) writing from the information terminal to the external storage medium the generated second management data and rights data, but not the encrypted content data, onto the external storage medium, responsive to the detecting means detecting the same encrypted content on the external storage medium.
2. The information terminal according to claim 1 , wherein both the first management data and the second management data include fourth identification information identifying the information terminal.
3. The information terminal according to claim 1 , further comprising means for detecting that another item of management data including the third identification information is present on the external storage medium, and for then controlling the generating means to generate the second management data to include relational information that identifies said another item of management data.
4. The information terminal according to claim 1 , further comprising means for detecting that another item of management data identifying the same content data is subsequently written onto the external storage medium, and for then revising the previously stored first or second management data to include relational information that identifies the subsequently stored item of management data.
5. The information terminal according to claim 1 , further comprising means for controlling the generating means to generate a plurality of items of management data that all include information identifying a same item of encrypted content data, such that each of said plurality of items of management data, except a last-generated one of said plurality of items, includes relational information that identifies a subsequently-generated one of said plurality of items of management data.
6. The information terminal according to claim 5 , wherein the last-generated one of the items includes relational information that identifies a first-generated one of the items.
7. The information terminal according to claim 1 , further comprising means for controlling the generating means to generate a plurality of items of management data that all include information identifying a same item of encrypted content data, such that each of said plurality of items of management data, except a first-generated one of said plurality of items, includes relational information that identifies a previously-generated one of said plurality of items of management data.
8. The information terminal according to claim 7 , wherein the last-generated one of the items includes relational information that identifies a first-generated one of the items.
9. The information terminal according to claim 1 , further comprising means for controlling the generating means to generate a plurality of items of management data that all include information identifying a same item of encrypted content data, such that each of said plurality of items of management data includes relational information that identifies each of the other ones of said plurality of items of management data.
10. The information terminal according to claim 1 , further comprising restoring means for restoring the item of encrypted content data and the corresponding item of rights data to an internal memory of the information terminal device.
11. An information terminal which manages encrypted content data and rights data used for decrypting the encrypted content data, and which is operable to store the encrypted content data and the rights data on an external storage medium, said information terminal comprising:
a detecting section which detects that an item of encrypted content data and an item of rights data corresponding thereto are to be stored on the external storage medium, and which then detects one of: (i) that a same encrypted content as the item of encrypted content data to be stored is already stored on the external storage medium, and (ii) that the same encrypted content as the item of encrypted content data to be stored is not already stored on the external storage medium;
a generating section which (i) generates, at the information terminal, first management data that includes first identification information identifying the item of encrypted content data and second identification information identifying the corresponding item of rights data, responsive to the detecting section not detecting the same encrypted content on the external storage medium, and (ii) generates, at the information terminal, second management data that includes third identification information identifying the item of encrypted content data already stored on the external storage medium and the second identification information identifying the item of rights data, responsive to the detecting section detecting the same encrypted content on the external storage medium; and
a writing section which (i) writes from the information terminal to the external storage medium the generated first management data, the encrypted content data, and the rights data onto the external storage medium, responsive to the detecting section not detecting the same encrypted content on the external storage medium, and (ii) writes from the information terminal to the external storage medium the generated second management data and rights data, but not the encrypted content data, onto the external storage medium, responsive to the detecting section detecting the same encrypted content on the external storage medium.
12. The information terminal according to claim 11 , wherein both the first management data and the second management data include fourth identification information identifying the information terminal.
13. The information terminal according to claim 11 , further comprising a control section which detects that another item of management data including the third identification information is present on the external storage medium, and which then controls the generating section to generate the second management data to include relational information that identifies said another item of management data.
14. The information terminal according to claim 11 , further comprising a control section which detects that another item of management data identifying the same content data is subsequently written onto the external storage medium, and which then revises the previously stored first or second management data to include relational information that identifies the subsequently stored item of management data.
15. The information terminal according to claim 11 , further comprising a control section which controls the generating section to generate a plurality of items of management data that all include information identifying a same item of encrypted content data, such that each of said plurality of items of management data, except a last-generated one of said plurality of items, includes relational information that identifies a subsequently-generated one of said plurality of items of management data.
16. The information terminal according to claim 15 , wherein the last-generated one of the items includes relational information that identifies a first-generated one of the items.
17. The information terminal according to claim 11 , further comprising a control section which controls the generating section to generate a plurality of items of management data that all include information identifying a same item of encrypted content data, such that each of said plurality of items of management data, except a first-generated one of said plurality of items, includes relational information that identifies a previously-generated one of said plurality of items of management data.
18. The information terminal according to claim 17 , wherein the last-generated one of the items includes relational information that identifies a first-generated one of the items.
19. The information terminal according to claim 11 , further comprising a control section which controls the generating section to generate a plurality of items of management data that all include information identifying a same item of encrypted content data, such that each of said plurality of items of management data includes relational information that identifies each of the other ones of said plurality of items of management data.
20. The information terminal according to claim 11 , further comprising a restoring section to restore the item of encrypted content data and the corresponding item of rights data to an internal memory of the information terminal device.