Common key sharing method and wireless communication terminal in ad hoc network

• US 20050215234A1
• Filed: 03/28/2005
• Published: 09/29/2005
• Est. Priority Date: 03/26/2004
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Fukuzawa, Yasuko, Ando, Eriko, Matsui, Susumu, Ishida, Shuichi
• Granted Patent: US 7,567,673 B2
• Time in Patent Office: Days
• US Class Current: 455/411
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 63/0435 wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06
• CPC Class Codes: H04L 63/062 for key distribution, e.g. centrally by trusted party cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819
• CPC Class Codes: H04L 63/0869 for achieving mutual authentication cryptographic mechanisms or cryptographic arrangements for mutual authentication H04L9/3273
• CPC Class Codes: H04L 9/0838 Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these network architectures or network communication protocols for key exchange in a packet data network H04L63/061
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04M 2203/2044 Group features, e.g. closed user group
• CPC Class Codes: H04M 2207/18 wireless networks
• CPC Class Codes: H04M 3/38 Graded-service arrangements, i.e. some subscribers prevented from establishing certain connections queuing arrangements H04Q3/64
• CPC Class Codes: H04M 7/00 Arrangements for interconnection between switching centres
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 12/50 Secure pairing of devices
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

The present invention relates to a common key sharing method in an ad hoc network constituted by wireless communication terminals implemented with relay functions thereon, comprising a common key generating step in which a first wireless communication terminal responsible for relaying generates a common key, a common key distributing step in which the first wireless communication terminal responsible for relaying distributes the common key to a second wireless communication terminal within a wireless communication area, and a transferring step in which the second wireless communication terminal which received the common key holds the common key, and the second wireless communication terminal transfers the common key to a third wireless communication terminal within a wireless communication area, when the second wireless communication terminal is responsible for relaying. Accordingly, it is possible to share a common encryption key within the ad hoc network.

Claims

1. A common key sharing method in an ad hoc network constituted by wireless communication terminals implemented with relay functions thereon, comprising:

a common key generating step in which a first wireless communication terminal responsible for relaying generates a common key;

a common key distributing step in which said first wireless communication terminal responsible for relaying distributes said common key to a second wireless communication terminal within a wireless communication area; and

a transferring step in which said second wireless communication terminal which received said common key holds said common key, and said second wireless communication terminal transfers said common key to a third wireless communication terminal within a wireless communication area, when said second wireless communication terminal is responsible for relaying.

2. The common key sharing method according to claim 1, further comprising,

an inter-transmission-area distributing step in which the first wireless communication terminal distributes an inter-transmission-area key to the second wireless communication terminal within the wireless communication area, wherein,

said inter-transmission-area distributing step encrypts said common key with said inter-transmission-area key, and distributes said common key thus encrypted.

3. The common key sharing method, according to claim 2, further comprising,

a mutual authentication step which performs mutual authentication between the first wireless communication terminal and the second wireless communication terminal within the wireless communication area, wherein,

said inter-transmission-area distributing step distributes said inter-transmission-area key to the second wireless communication terminal thus authenticated.

4. The common key sharing method according to any one of claims 1 to 3, wherein,

said common key is identifiable according to an identifier.

5. The common key sharing method, according to claim 4, wherein,

said identifier is generated, distributed, and transferred, together with said common key.

6. A wireless communication terminal implemented with a relay function for constituting an ad hoc network, comprising:

a network information generating means in which said wireless communication terminal sends/receives information regarding network configuration to/from a second wireless communication terminal within a wireless communication area and generates network configuration information;

a common key generating means in which said wireless communication terminal generates a common key when itself being determined as responsible for relaying based on said network configuration information;

a common key distributing means in which said wireless communication terminal distributes said common key thus generated to the second wireless communication terminal within the wireless communication area; and

a transferring means in which when the second wireless communication terminal receives said common key, the second wireless communication terminal holds said common key, and transfers said common key thus received to a third wireless communication terminal within the wireless communication area, when the second wireless communication terminal itself being determined as responsible for relaying.

7. The wireless communication terminal according to claim 6, further comprising an authentication means, which authenticates the second wireless communication terminal within the wireless communication area, wherein,

said network information generating means sends/receives the information regarding the network configuration to/from the second wireless communication terminal, which has been authenticated.

8. The wireless communication terminal according to claim 7, wherein,

said network configuration information is an information to recognize the wireless communication terminal constituting the ad hoc network, and

when the second wireless communication terminal having been authenticated moves out of the wireless communication area and the second wireless communication terminal is not recognized as the wireless communication terminal constituting the ad hoc network within a predetermined period of time, said common key generating means updates the common key, and said common key distributing means distributes said common key thus updated.

9. The wireless communication terminal according to claim 7, wherein,

said network configuration information is an information to recognize the wireless communication terminal constituting the ad hoc network, and

when the second wireless communication terminal having constituted the ad hoc network moves out of the ad hoc network and returns into the wireless communication area within a predetermined period of time, said authentication means does not authenticate the second wireless communication terminal.