Information processing scheme for realizing contents transfer and copyright protection

• US 20050216724A1
• Filed: 03/04/2005
• Published: 09/29/2005
• Est. Priority Date: 03/05/2004
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Saito, Takeshi, Isozaki, Hiroshi, Matsushita, Tatsuyuki, Kamibayashi, Tooru
• Granted Patent: US 8,041,949 B2
• Time in Patent Office: Days
• US Class Current: 713/150
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263

Abstract

In an information processing system in which a range of information transfer between communication devices through a network is limited within a prescribed range by registering unique information obtainable within the prescribed range into each device and permitting information transfer between devices which share common unique information, where the unique information is formed by a pair of a public unique information and a secret unique information, a bridge device is controlled such that, upon receiving a proxy check request from a reception device, whether a transmission device is another bridge device or not is judged when the public unique information registered by the reception device is registered in the bridge device and one public unique information registered in the bridge device is registered by the transmission device. Then, the secret unique information registered by the reception device is transmitted to the transmission device when the transmission device is not another bridge device.

Claims

1. A bridge device for bridging between communication devices in an information processing system in which a range of information transfer between communication devices through a network is limited within a prescribed range by registering unique information obtainable within the prescribed range into each device and permitting information transfer between devices which share common unique information, where the unique information is formed by a pair of a public unique information and a secret unique information, the bridge device comprising:

a unique information storing unit configured to store pairs of the public unique information and the secret unique information registered by the bridge device;

a proxy check request receiving unit configured to receive a proxy check request, the public unique information registered by a first communication device, and an address information of a second communication device which is an intended correspondent of the first communication device, from the first communication device;

a first judgement unit configured to judge whether the public unique information registered by the first communication device is registered in the unique information storing unit or not;

a second judgement unit configured to judge whether any public unique information registered in the unique information storing unit is registered by the second communication device or not;

a device type judgement unit configured to judge whether the second communication device is another bridge device or not, when the first judgement unit judges that the public unique information registered by the first communication device is registered in the unique information storing unit and the second judgement unit judges that one public unique information registered in the unique information storing unit is registered by the second communication device; and

a unique information transmission determining unit configured to determine whether or not to transmit the secret unique information registered by the first communication device to the second communication device, according to a judgement result of the device type judgement unit.

2. The bridge device of claim 1, wherein the unique information transmission determining unit is configured to determine not to transmit the secret unique information registered by the first communication device to the second communication device, when the device type judgement unit judges that the second communication device is another bridge device.

3. The bridge device of claim 1, further comprising:

a hop number judgement unit configured to judge whether a hop number is less than a prescribed threshold or not, when the device type judgement unit judges that the second communication device is another bridge device, the hop number indicating a number of other bridge devices which relayed the proxy check request before the proxy check request reaches to the bridge device;

wherein the unique information transmission determining unit is configured to determine to transmit the secret unique information registered by the first communication device to the second communication device when the hop number judgement unit judges that the hop number is less than the prescribed threshold, and determine not to transmit the secret unique information registered by the first communication device to the second communication device when the hop number judgement unit judges that the hop number is not less than the prescribed threshold.

4. The bridge device of claim 1, further comprising:

a routing list size judgement unit configured to judge whether a size of a routing list is less than a prescribed size or not, when the device type judgement unit judges that the second communication device is another bridge device, the routing list indicating a route by which the second communication device can be reached from the first communication device;

wherein the unique information transmission determining unit is configured to determine to transmit the secret unique information registered by the first communication device to the second communication device when the routing list size judgement unit judges that the size of the routing list is less than the prescribed size, and determine not to transmit the secret unique information registered by the first communication device to the second communication device when the routing list size judgement unit judges that the size of the routing list is not less than the prescribed size.

5. The bridge device of claim 1, wherein the second judgement unit comprises:

a check request unit configured to request the second communication device to check whether any public unique information registered in the unique information storing unit is registered by the second communication device or not, by transmitting the public unique information stored in the unique information storing unit to the second communication device, when the first judgement unit judges that the public unique information registered by the first communication device is registered in the unique information storing unit; and

a check result receiving unit configured to receive a check result which is obtained by the second communication device in response to the check request unit, and which indicates whether any public unique information registered in the unique information storing unit is registered by the second communication device or not.

6. The bridge device of claim 1, further comprising:

a first interface unit configured to receive a pair of the public unique information and the secret unique information possessed by a specific device, from the specific device, in a form in which at least the secret unique information is encrypted; and

a second interface unit configured to exchange the public unique information and the secret unique information possessed by the specific device in a form in which at least the secret unique information is encrypted, between the first communication device and the second communication device through the network;

wherein the unique information storing unit is configured to store the public unique information and the secret unique information received by the first interface unit as the public unique information and the secret unique information registered by the bridge device.

7. The bridge device of claim 6, wherein the first interface unit is configured to receive a pair of the public unique information and the secret unique information possessed by the specific device which is capable of communicating only with devices located within a limited range around the specific device.

8. The bridge device of claim 6, wherein the first interface unit is configured to receive a pair of the public unique information and the secret unique information possessed by the specific device which is an accessory to each communication device connected to the network which is a home network, and the bridge device functions as a home server.

9. A communication device in an information processing system in which a range of information transfer between communication devices through a network is limited within a prescribed range by registering unique information obtainable within the prescribed range into each device and permitting information transfer between devices which share common unique information, where the unique information is formed by a pair of a public unique information and a secret unique information, the communication device comprising:

a unique information storing unit configured to store a pair of the public unique information and the secret unique information registered by the communication device;

a check unit configured to check whether the secret unique information registered in the unique information storing unit is registered by another communication device which is an intended correspondent of the communication device or not;

a route search unit configured to produce a routing list indicating a route by which the another communication device can be reached from the communication device, by searching at least one bridge device for bridging between the communication device and the another communication device, when the check unit indicates that the secret unique information registered in the unique information storing unit is not registered by the another communication device;

a routing list size judgement unit configured to judge whether a size of the routing list is less than or equal to a prescribed size or not; and

a proxy check request transmission unit configured to transmit a proxy check request, the public unique information registered by the communication device, and an address information of the another communication device, to a first bridge device on the route when the routing list size judgement unit judges that the size of the routing list is less than or equal to the prescribed size.

10. The communication device of claim 9, further comprising:

a first interface unit configured to receive a pair of the public unique information and the secret unique information possessed by a specific device, from the specific device, in a form in which at least the secret unique information is encrypted; and

a second interface unit configured to exchange encrypted contents with other communication devices through the network;

wherein the unique information storing unit is configured to store the public unique information and the secret unique information received by the first interface unit as the public unique information and the secret unique information registered by the communication device.

11. The communication device of claim 10, wherein the first interface unit is configured to receive a pair of the public unique information and the secret unique information possessed by the specific device which is capable of communicating only with devices located within a limited range around the specific device.

12. The communication device of claim 10, wherein the first interface unit configured to receive a pair of the public unique information and the secret unique information possessed by the specific device which is an accessory to the communication device connected to the network which is a home network, and the bridge device functions as a home server.

13. A method for controlling a bridge device for bridging between communication devices in an information processing system in which a range of information transfer between communication devices through a network is limited within a prescribed range by registering unique information obtainable within the prescribed range into each device and permitting information transfer between devices which share common unique information, where the unique information is formed by a pair of a public unique information and a secret unique information, the method comprising:

(a) storing pairs of the public unique information and the secret unique information registered by the bridge device;

(b) receiving a proxy check request, the public unique information registered by a first communication device, and an address information of a second communication device which is an intended correspondent of the first communication device, from the first communication device;

(c) judging whether the public unique information registered by the first communication device is registered by the step (a) or not;

(d) judging whether any public unique information registered by the step (a) is registered by the second communication device or not;

(e) judging whether the second communication device is another bridge device or not, when the step (c) judges that the public unique information registered by the first communication device is registered by the step (a) and the step (d) judges that one public unique information registered by the step (a) is registered by the second communication device; and

(f) determining whether or not to transmit the secret unique information registered by the first communication device to the second communication device, according to a judgement result of the step (e).

14. A method for controlling a communication device in an information processing system in which a range of information transfer between communication devices through a network is limited within a prescribed range by registering unique information obtainable within the prescribed range into each device and permitting information transfer between devices which share common unique information, where the unique information is formed by a pair of a public unique information and a secret unique information, the method comprising:

(a) storing the public unique information and the secret unique information registered by the communication device;

(b) checking whether the secret unique information registered by the step (a) is registered by another communication device which is an intended correspondent of the communication device or not;

(c) producing a routing list indicating a route by which the another communication device can be reached from the communication device, by searching at least one bridge device for bridging between the communication device and the another communication device, when the step (b) indicates that the secret unique information registered in the unique information storing unit is not registered by the another communication device;

(d) judging whether a size of the routing list is less than or equal to a prescribed size or not; and

(e) transmitting a proxy check request, the public unique information registered by the communication device, and an address information of the another communication device, to a first bridge device on the route when the step (d) judges that the size of the routing list is less than or equal to the prescribed size.