摘要:
A key issuing center (11) distributes a system secret parameter group that is information necessary for generating a content key used for encrypting a content to a server (12), and an encrypted intermediate key group set that is information necessary for generating a content key used for decrypting the content to output apparatuses (13a to 13n). The server (12) generates the content key based on the system secret parameter group and a time varying parameter group, encrypts the content based on the content key, and distributes the encrypted content and the time varying parameter group to the output apparatuses (13a to 13n). The output apparatuses (13a to 13n) generates a content key based on the encrypted intermediate key group set and the received time varying parameter group, decrypts the encrypted content based on the content key, and outputs to outside.
摘要:
The cloning source of an authorized receiving device cannot be identified. A key distribution system 1 concerning the present invention includes: a communication channel 10; a key distribution center 11; a server 12; and receiving devices 13a to 13n. The key distribution center 11 distributes, to the server 12, the information necessary for distributing shared keys SK to the receiving devices 13a to 13n, and distributes the individual information group EMMG necessary for receiving the shared keys SK from the server 12. The server 12 generates the shared keys SK, generates the common information ECM based on the shared keys SK and the system secret variable group set SPGS, and distributes the common information ECM to the receiving devices 13a to 13n. The receiving devices 13a to 13n obtain the shared keys SK based on the individual information group EMMG and the common information ECM and outputs them to outside.
摘要:
A content distribution system distributes contents. The content distribution system includes a key issuing center, a server, eight output apparatuses, and a communication path that connects them to each other. The key issuing center and each of the output apparatuses are previously given an individual key shared between them. For example, the key issuing center shares individual key IKa with an output apparatus, individual key IKb with an output apparatus, and individual key IKh with an output apparatus.
摘要:
The present invention is a content distribution system for distributing contents. The content distribution system (1) includes a key issuing center (11), a server (12), eight output apparatuses (13a) to (13h), and a communication path (10) that connects them to each other. Here, a pair of the key issuing center (11) and each of the output apparatuses (13a) to (13h) is previously given an individual key shared between them. For example, the key issuing center (11) shares an individual key IKa with the output apparatus (13a), an individual key IKb with the output apparatus (13b), and an individual key IKh with the output apparatus (13h).
摘要:
A key management apparatus which can be used to encrypt/decrypt content data in a content playback device includes a storing unit for storing a secret key, a key information decrypting unit for decrypting encrypted key information and an updating unit operable to update the secret key with an algorithm stored therein, when the decrypted key information is key-updating information. Seed information can be received for use with the algorithm to provide a new secret key, and preliminary trigger information can be used to poll a group of appliances to request key information to determine any duplication of appliances.
摘要:
The present invention provides a technique which makes it possible to eliminate unauthorized playback of contents where unauthorized apparatuses are used and enable only authorized playback apparatuses to play back contents properly. The playback apparatus of the present invention obtains encrypted key information that has been encrypted by a first secret-key encrypting method, and decrypt the encrypted key information into key information using a secret key stored in a storing unit. When the key information is key-updating information, the playback apparatus updates the secret key according to the key-updating information. When the key information is a decryption key, the playback apparatus (i) obtains an encrypted content key that has been encrypted by a second secret-key encrypting method, (ii) decrypts the encrypted content key into a content key using the decryption key, (iii) obtains a scrambled content that has been scrambled by a scramble encrypting method, (iv) descramble the scrambled content using the decrypted content key, and (v) plays back the descrambled content.