COMMUNICATION METHOD, NODE, AND NETWORK SYSTEM

• US 20130312082A1
• Filed: 07/29/2013
• Published: 11/21/2013
• Est. Priority Date: 01/31/2011
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: IZU, Tetsuya, TAKENAKA, Masahiko, FURUKAWA, Kazuyoshi, KOJIMA, Hisashi
• Granted Patent: US 9,203,800 B2
• Time in Patent Office: Days
• US Class Current: 726/13
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 63/02 for separating internal from external traffic, e.g. firewalls
• CPC Class Codes: H04L 63/126 the source of the received data
• CPC Class Codes: H04L 63/1458 Denial of Service
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying

Abstract

A communication method executed by a node in an ad hoc network having multiple nodes, includes receiving from a neighboring node of the node in the ad hoc network, a first packet that includes a sender address of the neighboring node and a first packet transmission count of packet transmissions from the neighboring node; extracting the first packet transmission count from the first packet; receiving from the neighboring node and after reception of the first packet, a second packet that includes the sender address of the neighboring node and a second packet transmission count of packet transmissions from the neighboring node; extracting the second packet transmission count from the second packet; determining whether the second packet is an invalid packet, based on the first packet transmission count and the second packet transmission count; and discarding the second packet upon determining the second packet to be an invalid packet.

Claims

1. A communication method executed by a node in an ad hoc network having a plurality of nodes, the communication method comprising:

receiving from a neighboring node of the node in the ad hoc network, a first packet that includes a sender address of the neighboring node and a first packet transmission count of packet transmissions from the neighboring node;

extracting the first packet transmission count from the first packet;

receiving from the neighboring node and after reception of the first packet, a second packet that includes the sender address of the neighboring node and a second packet transmission count of packet transmissions from the neighboring node;

extracting the second packet transmission count from the second packet;

determining whether the second packet is an invalid packet, based on the first packet transmission count and the second packet transmission count; and

discarding the second packet upon determining the second packet to be an invalid packet.

2. A communication method executed by a node in an ad hoc network having a plurality of nodes, the communication method comprising:

detecting an event of packet transmission by the node to a neighboring node of the node in the ad hoc network;

updating upon detecting the event of packet transmission, a packet transmission count of packet transmissions from the node, the packet transmission count being retained in a storage device of the node and updated to a value obtained by adding 1 to the packet transmission count; and

transmitting to the neighboring node, a packet that includes the updated packet transmission count.

3. The communication method according to claim 2, further comprising:

sensing a deletion of the packet transmission count retained in the storage device of the node;

notifying upon sensing the deletion of the packet transmission count, the neighboring node of a request packet requesting the packet transmission count that is for the node and retained in the storage device of the neighboring node;

receiving from the neighboring node in response to the request packet, a response packet that includes the packet transmission count for the node;

extracting from the response packet, the packet transmission count for the node; and

storing to the storage device of the node, the extracted packet transmission count for the node.

4. The communication method according to claim 3, further comprising:

encrypting the request packet using a common key that the nodes in the ad hoc network have; and

decrypting the response packet by using the common key, the response packet having been encrypted by the neighboring node using the common key, wherein

the notifying includes notifying the neighboring node of the encrypted request packet,

the receiving includes receiving from the neighboring node, the response packet encrypted using the common key,

the decrypting includes decrypting the response packet from the encrypted response packet, and

the extracting includes extracting from the decrypted response packet, the packet transmission count for the node.

5. The communication method according to claim 3, wherein

the notifying includes notifying the neighboring node of the request packet that is encrypted and includes first identification information unique to the node,

the receiving includes receiving from the neighboring node, the response packet that is encrypted using a common key and includes second identification information,

the extracting includes extracting the second identification information from the response packet decrypted from the encrypted response packet received, and

the storing includes storing to the storage device of the node, the extracted packet transmission count for the node, when the first identification information coincides with the extracted second identification information.

6. The communication method according to claim 5, further comprising

generating a random number as the first identification information.

7. The communication method according to claim 3, further comprising:

receiving from the neighboring node and after sensing the deletion, a second common key that the neighboring node has and that is encrypted using a first common key that the nodes in the ad hoc network have;

decrypting the second common key from the encrypted second common key, by using the first common key;

encrypting the request packet using the decrypted second common key; and

decrypting, by using the decrypted second common key, the response packet encrypted using the second common key by the neighboring node, wherein

the notifying includes notifying the neighboring node of the encrypted request packet,

the receiving includes receiving from the neighboring node, the response packet encrypted using the second common key,

the decrypting includes decrypting the response packet from the encrypted response packet, and

the extracting includes extracting from the decrypted response packet, the packet transmission count for the node.

8. The communication method according to claim 3, wherein

the notifying includes notifying the neighboring node of the request packet that is encrypted and includes first identification information unique to the node,

the receiving includes receiving from the neighboring node, the response packet that is encrypted using the second common key and includes second identification information, wherein

the extracting includes extracting the second identification information from the response packet decrypted from the encrypted response packet received, and

the storing includes storing to the storage device of the node, the extracted packet transmission count for the node, when the first identification information coincides with the extracted second identification information.

9. The communication method according to claim 8, further comprising

generating a random number as the first identification information.

10. A network system comprising:

a node in an ad hoc network having a plurality of nodes and a neighboring node of the node in the ad hoc network, wherein the node includes;

a processor configured to;

detect an event of packet transmission to a neighboring node of the node in the ad hoc network,

update upon detecting the event of packet transmission, a first packet transmission count of packet transmissions from the node, the first packet transmission count being retained in a storage device of the node and updated to a value obtained by adding 1 to the first packet transmission count, and

transmit to the neighboring node, a first packet that includes the updated first packet transmission count; and

the neighboring node includes;

a processor configured to;

receive the first packet transmitted from the node,

extract the first packet transmission count from the received first packet,

receive after receiving the first packet, a second packet that includes a sender address of the node and a second packet transmission count of transmissions from the node,

extract the second packet transmission count from the received second packet,

determine whether the second packet is an invalid packet, based on the extracted first packet transmission count and on the extracted second packet transmission count, and

discard the second packet upon determining the second packet to be an invalid packet.