INFORMATION PROCESSING APPARATUS, AUTHENTICATION METHOD, AND STORAGE MEDIUM
First Claim
Patent Images
1. A storage medium comprising:
- an encrypted content;
key management information which is updated whenever necessary and includes a media key block including encrypted media keys obtained by encrypting a media key which is a base of an authentication key used for mutual authentication with another apparatus by using different device keys; and
first and second application keys which encrypt the title keys for each application of the content and are alternately updated and encrypted when the key management information is updated.
1 Assignment
0 Petitions
Accused Products
Abstract
According to one embodiment, a storage medium comprises an encrypted content, key management information which is updated whenever necessary and includes a media key block including encrypted media keys obtained by encrypting a media key which is a base of an authentication key used for mutual authentication with another apparatus by using different device keys, and first and second application keys which encrypt the title keys for each application of the content and are alternately updated and encrypted when the key management information is updated.
82 Citations
12 Claims
-
1. A storage medium comprising:
-
an encrypted content; key management information which is updated whenever necessary and includes a media key block including encrypted media keys obtained by encrypting a media key which is a base of an authentication key used for mutual authentication with another apparatus by using different device keys; and first and second application keys which encrypt the title keys for each application of the content and are alternately updated and encrypted when the key management information is updated. - View Dependent Claims (2, 3, 4, 5)
-
-
6. An information processing apparatus configured to access a storage medium which stores an encrypted content, title keys configured to encrypt the content, key management information, and first and second application keys configured to encrypt the title keys for each application of the content, comprising:
-
a management information update module configured to update the key management information; and a key update module configured to alternately update the first and second application keys when the key management information is updated. - View Dependent Claims (7, 8, 9)
-
-
10. An authentication method for an information processing apparatus configured to access a storage medium which stores
first key management information which is updated whenever necessary, title keys configured to encrypt the content, and encrypted media keys obtained by encrypting a media key which is a base of an authentication key used for mutual authentication with another apparatus by using different device keys; -
first and second application keys which encrypt the title keys for each application of the content; and update count information of the first key management information, the information processing apparatus configured to store a second key management information which is updated whenever, the method comprising; (i) reading the first key management information from the storage medium, collating the first and second key management information, sending the second key management information to the storage medium, when the second key management information is newer than the first key management information, and updating the first key management information to the second key management information; (ii) obtaining the authentication key from the first key management information read from the storage medium, and making mutual authentication with the storage medium by using the authentication key; (iii) sending a media key prim request to the storage medium, and obtaining an expected value of a media key prim response from the media key, when the mutual authentication is successful; (iv) obtaining a candidate value of a media key prime from a media key in the storage medium receiving the media key prime request, and sending the candidate value to the information processing apparatus; and (v) collating the obtained expected value of media key prime and the received candidate value of media key prime, and updating the first and second application keys alternately according to the update count of the first key management information, when the expected value coincides with the candidate value. - View Dependent Claims (11, 12)
-
Specification