Patent ID: 7757087
Filing Date: 2010-07-13
Classification: G06F,H04L

Abstract:
1. An information processing apparatus configured to receive encrypted contents and key information attached to the contents transmitted from a communication apparatus connected via a network, the information apparatus comprising: an authentication and key exchange unit configured to perform authentication and key exchange processing by using a given protocol with the communication apparatus and to generate a first key shared with the communication apparatus; a contents receiver configured to receive the encrypted contents obtained by encrypting the contents with a second key, generated by using the first key and the key information, and to receive the key information attached to the encrypted contents, the key information being updated after transmission of a predetermined amount of contents; a contents decryption unit configured to decrypt the encrypted contents by using the first key and the key information; a contents confirmation request unit configured to transmit to the communication apparatus a contents confirmation request for transmitting or confirming the key information held by the communication apparatus when the contents decryption unit decrypts the contents based on the second key, the contents confirmation request including a first random number; a key information confirmation unit configured to receive the key information or a confirmation result of the key information, the key information being encrypted by using the first key and the first random number, and being transmitted from the communication apparatus in response to the contents confirmation request to confirm whether or not a comparison between the received key information and the key information received by the contents receiver is successful; a first communication connection to communicate the encrypted contents and the key information attached to the encrypted contents; and a second communication connection to communicate authentication and key exchange processing, and either of the encrypted key information or the encrypted confirmation result of the key information.