Content protection method, and information recording and reproduction apparatus using same
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsYoshimitsu Nakamura, Kiyoshi Tominaga
Life of this patent
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Abstract
In content protection method and apparatus, a title key invalidation information is generated for invalidating a title key corresponding to a content in a medium and a content key is generated from the title key and the title key invalidation information. The content is encrypted based on the content key. The title key invalidation information is changed in case of removing or moving the content from the medium and the changed title key invalidation information is stored in the medium. Therefore, the content is prevented from being replicated while enabling the content to be reproduced in another medium.
Claims8
A content protection method comprising the steps of:
- generating a title key invalidation information for invalidating a title key corresponding to a content in a medium;
- generating a content key from the title key and the title key invalidation information;
- encrypting the content based on the content key;
- changing the title key invalidation information in case of removing or moving the content from the medium;
- and
- storing the changed title key invalidation information in the medium.
An information recording and reproduction apparatus comprising:
- a first generating unit for generating a title key invalidation information for invalidating a title key corresponding to a content in a medium;
- a second generating unit for generating a content key from the title key and the title key invalidation information;
- a first encrypting unit for encrypting the content based on the content key;
- a changing unit for changing the title key invalidation information in case of removing or moving the content from the medium;
- and
- a first storing unit for storing the changed title key invalidation information in the medium.
Dependencies are inferred from the claim text.