JP4020108B2 - AD HOC NETWORK COMMUNICATION METHOD AND METHOD, NODE DEVICE, AND ITS PROGRAM - Google Patents

Description

  The present invention relates to an ad hoc network communication method and method, a node device, and a program thereof, and more particularly to an ad hoc network communication method and method, a node device, and a program thereof that securely exchange data between nodes.

  An example of a conventional ad hoc network system is shown below.

  In Patent Document 1, whether or not an existing network master has been removed is checked, and if it is confirmed that the existing network master has been removed, the existing network master is used to select a new network master. Check the order received previously. If the rank is the highest priority over the ranks of many slaves, his role is changed to a new network master.

  Further, in Patent Document 2, in a star-type ad-hoc wireless LAN system, the parent device periodically predicts the battery run-out time of the own device and makes all the child devices predict the battery run-out time of the own device. Then, it collects estimated battery time information of all terminals, and selects the terminal with the longest estimated battery time as the parent device.

  In Patent Document 3, in a mobile terminal network (ad hoc network), data transmitted from a transmission terminal is transferred to a reception terminal via a relay terminal and a representative terminal.

JP 2002-1111689 A JP 2003-32263 A JP 2004-80642 A

  However, the background art described above has the following problems.

  That is, in an ad hoc network constituted by a set of non-fixed terminals, it is impossible to perform secret communication for safely transferring data and the like between nodes.

  An object of the present invention is to solve the above problems and provide an ad hoc network communication method and method, a node device, and a program thereof that can safely exchange data and the like between nodes.

  The ad hoc network communication system according to the first aspect of the present invention is an ad hoc network communication system in which a plurality of nodes form an ad hoc network for communication, and means for selecting a representative node among the plurality of nodes; Means for exchanging trust information between a node and another node (delegation node) to establish a trust space, and relaying data transmission / reception between a source delegation node and a destination delegation node to the representative node, Means for performing secret communication based on the trust information.

  An ad hoc network communication system according to a second invention of the present application is characterized in that, in the first invention, the trust information includes a public key certificate.

  The ad hoc network communication system according to the third invention of the present application is capable of directly communicating the created list (own list) with means for creating a list of nodes that the own node can directly communicate with in the first or second invention. Means for transmitting data to a remote node, means for comparing the own list with a list received from another node (other list), means for controlling the own node as a representative node when there are a large number of nodes listed in the own list, And a means for controlling the own node as a delegation node when the number of nodes listed in the own list is small.

  The ad hoc network communication system according to the fourth invention of the present application is that when the transmission source delegation node transmits data to the transmission destination delegation node in the second or third invention, the transmission data is encrypted with the public key of the representative node. Means for signing with a secret key of the source node and transmitting to the representative node; and when the representative node receives data from the source delegation node, the received data is verified with the public key of the source delegation node and Decrypting with the private key of the node to extract the received data in a readable state, encrypting the extracted data with the public key of the destination delegating node, signing with the private key of the own node, and sending it to the destination delegating node When the destination delegation node receives data from the representative node, the signature of the received data is verified with the public key of the representative node And means for retrieving by the reception data into a readable state and decrypted with private key over de.

  The ad hoc network communication system according to a fifth invention of the present application is characterized in that, in the first invention, the representative node notifies the delegation node of the departure from the network and selects a next representative node from the delegation nodes; The elected next representative node includes means for exchanging trust information with the delegation node to establish a new trust space.

  An ad hoc network communication method according to a sixth invention of the present application is an ad hoc network communication method in which a plurality of nodes form an ad hoc network for communication, and a representative node is selected between the plurality of nodes, A trust space is established by exchanging trust information with another node (delegation node), and data transmission / reception between the source delegation node and the destination delegation node is relayed to the representative node and based on the trust information Secret communication is performed.

  An ad hoc network communication method according to a seventh invention of the present application is characterized in that, in the sixth invention, the trust information includes a public key certificate.

  The ad hoc network communication method according to the eighth invention of the present application creates a list that lists nodes with which the own node can communicate directly in the sixth or seventh invention, and is capable of directly communicating the created list (own list). Compare the own list with the list received from other nodes (other lists), and control the own node as a representative node when there are many nodes listed in the own list, and the number of nodes listed in the own list. When there are few, it controls the own node as a delegation node.

  The ad hoc network communication method according to the ninth invention of the present application is such that when the transmission source delegation node transmits data to the transmission destination delegation node in the seventh or eighth invention, the transmission data is encrypted with the public key of the representative node. And the signature node is transmitted to the representative node. When the representative node receives data from the transmission source delegation node, the signature of the received node is verified with the public key of the transmission source delegation node. Decrypt with the private key to make the received data readable, encrypt the retrieved data with the public key of the destination delegation node, sign with the private key of the node, and send to the destination delegation node When the destination delegation node receives data from the representative node, the received data is verified with the public key of the representative node and the private key of the own node Goka to take out by the received data into a readable state, and wherein the.

  In an ad hoc network communication method according to a tenth aspect of the present invention, in the sixth aspect, the representative node notifies the delegation node of the departure from the network, selects a next representative node from the delegation nodes, and is selected. The next representative node establishes a new trust space by exchanging trust information with the delegation node.

  A node device according to an eleventh invention of the present application is a node device that performs communication by forming an ad hoc network, and creates a list that lists other nodes that can communicate directly, and the created list (own list) Representing the own node when there are a large number of nodes enumerated in the own list, means for comparing the own list with a list received from another node (other list) Means for controlling as a node, means for controlling the own node as a delegation node when the number of nodes listed in the own list is small, means for transmitting trust information to the representative node in the case of the delegation node, and the representative node Means for exchanging trust information with the delegation node to establish a trust space, and in the case of the delegation node, the secret communication is performed based on the trust information Relaying over de and means for transmitting data to other delegated node.

  In the node device of the twelfth invention of the present application, in the eleventh invention, the trust information transmitted in the case of the delegation node includes the public key certificate of the own node, and the trust information transmitted in the case of the representative node is , Including the public key certificate of the own node encrypted with the public key of the delegation node.

  The node device according to the thirteenth invention of the present application is the representative of the twelfth invention in which the data to be transmitted to the destination delegation node is encrypted with the public key of the representative node and signed with the private key of the own node in the case of the transmission source delegation node. Means for transmitting to the node, and in the case of the representative node, the data received from the source delegation node is verified with the public key of the source delegation node and decrypted with the private key of the own node to make the received data readable Means for encrypting the extracted data with the public key of the destination delegation node, signing it with the private key of its own node and transmitting it to the destination delegation node; and data received from the representative node in the case of the destination delegation node Means for verifying the signature with the public key of the representative node, decrypting it with the private key of the own node, and taking out the received data in a readable state.

  In the eleventh aspect of the present invention, the node device according to the fourteenth aspect of the invention comprises means for notifying the delegation node of the departure from the network in the case of the representative node and selecting a next representative node from among the delegation nodes. In this case, there is provided means for controlling the own node as a representative node when it is elected as the next representative node and exchanging trust information with the delegation node to establish a new trust space.

  The program of the fifteenth invention of the present application is a program of a node device that performs communication by forming an ad hoc network, and has a function of creating a list that lists other nodes that can communicate directly with the node device, the created list A function for transmitting (own list) to another node that can communicate directly, a function for comparing the own list with a list (other list) received from another node, and when there are many nodes listed in the own list As a representative node, a function for controlling the own node as a delegation node when the number of nodes listed in the own list is small, a function for transmitting trust information to the representative node in the case of the delegation node, A function for establishing trust space by exchanging trust information with a delegation node, and for the delegation node, a secret communication based on the trust information It was carried out by relaying a representative node to realize the function, to transmit data to another delegation node.

  The program of the sixteenth invention of the present application is a function in which the trust information transmitted in the case of the delegation node in the fifteenth invention includes the public key certificate of the own node, and the trust information transmitted in the case of the representative node is A function including a node public key certificate encrypted with the public key of the delegation node is realized.

  The program of the seventeenth invention of the present application uses the representative node by encrypting the data to be transmitted to the destination delegation node in the sixteenth invention with the public key of the representative node and signing it with the private key of the own node. In the case of a representative node, the data received from the source delegation node is verified with the public key of the source delegation node, decrypted with the private key of the own node, and the received data is extracted in a readable state A function of encrypting the extracted data with the public key of the destination delegation node, signing it with the private key of its own node and transmitting it to the destination delegation node; in the case of the destination delegation node, the data received from the representative node The function of verifying the signature with the public key and decrypting it with the private key of the own node to retrieve the received data in a readable state is realized.

  In the fifteenth aspect of the present invention, the program according to the eighteenth aspect of the present invention is a function for notifying the delegation node of the departure from the network in the case of the representative node in the fifteenth aspect and selecting the next representative node from among the delegation nodes. When the node is selected as the next representative node, the function of establishing a new trust space by controlling the own node as a representative node and exchanging trust information with the delegation node is realized.

  An effect of the present invention is that secure data exchange can be performed in an ad hoc network.

  The reason is that a representative node is selected in the ad hoc network, trust information is exchanged between the representative node and another node, a trust space is established, and secret communication based on the trust information is performed.

  The present invention is characterized in that, in a network called an ad hoc network where nodes are not fixedly installed, documents, messages, and the like created on the network are safely exchanged between the nodes.

  More specifically, a representative node is set between each node in an ad hoc network configured by a network such as a wireless LAN. The representative node is used as a relay point for trust information, and a function for generating trust information and bypassing data is provided. Thereby, secret communication can be performed between nodes that do not have a direct communication path.

Next, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 2 is a diagram showing the configuration of the embodiment of the present invention.

  Referring to FIG. 2, the present embodiment includes a node a10, a node b20, a node c30, a node d40, and a node e50 that desire to participate in the ad hoc network. Each node is connected by a network such as a wireless LAN. In the ad hoc network shown in the present embodiment, the node a10 is only the node c30, the node b20 is only the node c30, the node c30 is the node a10, the node b20, the node d40, and the node from the physical characteristics (from the communication area and the like) It is assumed that a direct communication path can be ensured for e50 and node d40 only for node c30, and for node e50 only for node c30. That is, it is a star network, and communication data cannot be directly exchanged between two nodes between nodes other than the above. Also, it is assumed that the nodes participating in the ad hoc network trust each other in advance.

  Each node includes a storage unit that stores data and the like and a CPU (central processing unit) that controls the whole, and is operated by program control. For example, each node is a portable terminal such as a notebook personal computer. The storage unit includes a RAM (Random Access Memory) as a main storage device, a ROM (Read Only Memory) for storing programs, an auxiliary storage device for assisting the main storage device, and the like. Each node has an address for accessing the network. For example, if the network is a wireless LAN network, it has a LAN address.

Each node includes the following means.
(1) The transmission unit has a function of transmitting data to other nodes.
(2) The receiving means has a function of receiving data from other nodes.
(3) The key generation unit generates a secret key and a public key by a known method and stores them in the storage unit. The key generation means generates a public key certificate that certifies the generated public key by a known method and stores it in the storage unit. In the following description, the private key, public key, and public key certificate of the node a10 are represented as private key a, public key a, and public key certificate a. The same applies to private keys, public keys, and public key certificates of other nodes.
(4) The encryption unit has a function of encrypting data to be transmitted to another node with the public key of the node.
(5) The decryption means has a function of decrypting data from another node with the private key of the own node and storing it in the storage unit.
(6) The signing means has a function of signing data with a secret key. The signature depends on a known method.
(7) The node recognizing unit has a function of recognizing the presence of another node in the network that can directly communicate with the own node by a known method. The node recognizing unit creates a list indicating a list of nodes that can directly communicate based on the recognized node. A list is a format in which node names are listed after the list name. This list includes its own node. In the following description, the list created by the node a10 is represented as list a. The same applies to lists created by other nodes. In the example of FIG. 2, in the case of the node a10, the list a (node a, node c) is obtained.
(8) The delegation / representative selection means compares the own list with the list of other nodes, and if the number of nodes enumerated in the own list is large, the delegation / representative selection means is set as the representative node and the number of nodes enumerated in the own list is small In this case, the own node is set as the delegation node. The representative node is a node that represents the ad hoc network, and the delegation node is a node that delegates data exchange in communication with other nodes to the representative node. In the example of FIG. 1, the node c30 is a representative node, and the node a10, the node b20, the node d40, and the node e50 are delegation nodes.
(9) The representative node means operates when the delegation / representative selection means sets the own node as the representative node. The representative node means has a function of transmitting its own public key and public key certificate to the delegation node in order to form a trust relationship with the delegation node. Also, it has a function of receiving data from the delegation node and transferring the data to another delegation node that is the destination. When the representative node means operates, the delegation node means stops.
(10) The delegation node means operates when the delegation / representation selection means uses the own node as a delegation node. The delegation node means has a function of transmitting trust information (such as a public key and a public key certificate) to the representative node in order to form a trust relationship with the representative node. The delegation node means has a function of transmitting data to the representative node when transmitting data to another node. When data is received from another node, data is received from the representative node.

  Next, the operation of the best mode for carrying out the present invention will be described in detail with reference to the drawings.

First, the operation until each node shown in FIG. 2 is connected by trust information to form a trust space will be described with reference to FIGS.
FIG. 1 is a diagram illustrating a trust space between nodes.
FIG. 3 is a diagram for explaining the operation of the node a.
FIG. 4 is a diagram for explaining the operation of the node c.

  Assume that node a10, node b20, node c30, node d40, and node e50 are targeted as candidates for configuring the ad hoc network.

  First, each node recognizes the presence of another node in the ad hoc network by the node recognition means.

  Each node creates a list of nodes with which the node can directly communicate, and distributes the list to nodes that can communicate directly. In the configuration of FIG. 2, the node a10 is a list a (node a, node c), the node b20 is a list b (node b, node c), and the node c30 is a list c (node a, node b, node c, node d, Node e), node d40 are distributed to list d (node c, node d), and node e50 is list e (node c, node e) to the nodes described in the lists (list exchange between nodes). ).

  The operation of the node a10 at the time of list exchange will be described.

  Since the node a10 can communicate directly with the node c30, the node a10 transmits the list a (node a, node c) to the node c30.

  Since the node c30 can directly communicate with the node a10, similarly, the list c (node a, node b, node c, node d, node e) is transmitted to the node a10.

  Thereafter, the node a10 compares the list a (node a, node c) transmitted from the node itself with the list c (node a, node b, node c, node d, node e) received from the node c30. The node a10 confirms from the comparison result of these two lists that all the nodes described in the list a are included in the list c.

  At this time, the node a10 determines to delegate data exchange in communication with the nodes described in the list a to the node c30. Therefore, the node a10 transmits its own public key certificate a111 to the node c30 in order to establish trust with the node c30 (see FIG. 3).

  The above operation is also applied to the nodes b20, d40, and e50 having the same configuration.

  Next, the operation of the node c30 at the time of list exchange will be described.

  Since the nodes that can communicate directly with each other are the node a10, the node b20, the node d40, and the node e50, the node c30 transmits the list c (node a, node b, node c, node d, node e) to these nodes. .

  Further, since the node a10, the node b20, the node d40, and the node e50 can directly communicate with the node c30, the list a (node a, node c) and the list b (node b, node c) are respectively described according to the above description. ), List d (node c, node d), and list e (node c, node e) are transmitted to node c30.

  After that, the node c30 transmits the list c (node a, node b, node c, node d, node e) transmitted from the own node and the list a, list b, received from the node a10, node b20, node d40, and node e50. Compare list d and list e. From the comparison results of these lists, it is confirmed that the list c includes all the nodes described in the list received from another node. Further, the node c30 recognizes that its own node is the representative node because the number of nodes listed in the list c is the largest compared to the other lists.

  At this time, the node c30 acquires the public key of each node and the public key certificate that proves it from the nodes listed in the list c issued by the node, and acquires the trust information of each node.

  After that, the node c30 generates a public key certificate c311, a public key c, and a private key c that are trusted only by the group of nodes listed in the list c. The generated public key certificate c311 and public key c are distributed to each node listed in the list c. That is, the public key certificate c311 is encrypted with the public key a of the node a and transmitted to the node a. Similarly, the public key certificate c311 is encrypted with the public key b of the node b, encrypted with the public key d of the node d, encrypted with the public key d of the node d, encrypted with the public key e of the node e, and the node e Send to. In this way, a mutual trust space A is established between the nodes (see FIG. 4).

  When the processing described above is completed, the nodes are connected by a trust space A centered on the node c30 (see FIG. 1).

Next, an operation when a certain node transmits a message to another node after the trust space is formed will be described with reference to FIGS.
FIG. 5 is a diagram for explaining the operation of the node a.
FIG. 6 is a diagram for explaining the operation of the node c.

  In this example, an operation when the node a10 transmits a message having the same content to all the nodes of the ad hoc network in which the node a10 participates (that is, the node b20, the node c30, the node d40, and the node e50) will be described.

  First, the node a10 performs encryption with the public key c issued by the node c30 in order to conceal the data a transmitted from a node (not shown) that has not entered the trust space. Further, in order to prove that the data a is transmitted from the node a10, the data a is signed with the secret key a of the node a10 (data a121 in FIG. 5). The node a10 transmits the encrypted data a121 to the node c30 that is the representative node of the trust space A configured by the transmission destination node (see FIG. 5).

  The node c30 holds a public key a that can decrypt data encrypted with the secret key a and a secret key c that can decrypt data encrypted with the public key c. The node c30 verifies the signature of the data a121 transmitted by the node a10 with the public key a, and confirms that the data a121 is surely transmitted from the node a10. Also, the encryption of the data a121 is decrypted with the secret key c, and the data a transmitted by the node a10 is made readable. At this point, the node c30 has acquired the data a from the node a10.

Next, the node c30 transmits the data a to each node in the trust space A configured with itself as a representative node.
At this time, the node c30 encrypts the data a with the public key of each node acquired in the trust establishment process. That is, the data encrypted with the public key b acquired from the node b20 is stored in the node b20, the data encrypted with the public key d acquired from the node d40 is stored in the node d40, and the public data acquired from the node e50 is stored in the node e50. Data encrypted with the key e is transmitted. At this time, each encrypted data is signed with a private key c owned only by the node c30 in order to ensure that it is sent from the node c30.

  Next, an operation in which the node b20, the node d40, and the node e50 acquire the encrypted data transmitted from the node a10 to each node will be described. Here, as an example, a case where data a is transmitted to the node b20 will be described.

  As described above, the data a from the node c30 to the node b20 is encrypted with the public key b of the node b20 owned by the node c30. By doing so, nodes other than the node b20 cannot read the data a. Further, in order to prove that the data a is surely transmitted from the node c30 trusted by the node b20, the data a is signed with the secret key c.

  After performing the above processing, the node c30 transmits data a321 to the node b20.

  Since the node b20 that has received the data a321 from the node c30 owns the public key c distributed from the node c30, it verifies the signature of the data a321 using it. After the verification is successful, the node b20 decrypts the data a321 with its private key b, and acquires the data a in a readable state.

  Similarly, the node c30 transmits data a322 to the node d40 and data a323 to the node e50. Similarly, the node d40 and the node e50 perform the above operation, and all the nodes acquire the data a transmitted by the node a10 (see FIG. 6).

  The effect described by the above embodiment is that an ad hoc network that does not have a stationary node configuration can perform secure data exchange equivalent to a network that has a stationary node configuration. The reason is that a representative node is selected by exchanging a list representing the node connection state in the ad hoc network, and a trust space A centered on the representative node is established, and the representative node is valid only in the trust space A. This is because encryption that can be processed only in the trust space A can be performed by generating the trust information.

  Next, another embodiment of the present invention will be described in detail with reference to the drawings.

First, the configuration of another embodiment of the present invention will be described with reference to the drawings.
FIG. 7 is a diagram showing the configuration of another embodiment of the present invention.

  Referring to FIG. 7, another embodiment of the present invention includes a node a60, a node b70, a node c80, a node d90, and a node e100, and the nodes are connected by a network such as a radio. . It is assumed that the trust space described in the first embodiment is established with the node c80 as a representative node.

Each node has a function equivalent to the node of the first embodiment described above, and further has the following functions.
(1) The representative node means has a function of transmitting a representative node leaving notification to the delegation node. It also has a function of determining the next representative node and notifying each node. As a method for determining the next representative node, for example, the node that first transmitted the representative node acquisition request notification to the representative node may be determined as the next representative node.
(2) The delegation node means has a function of receiving a representative node leaving notification from the representative node and transmitting a representative node acquisition request notification to the representative node.
(3) The delegation / representation selection means sets the own node as the representative node when the own node is the next representative node in the notification of the determination of the next representative node received from the representative node. The representative node means operates and the delegation node means stops.

Next, the operation of another embodiment of the present invention will be described with reference to FIGS.
FIG. 8 is a diagram for explaining the operation of the node a.
FIG. 9 is a diagram for explaining the operation of the node c.
FIG. 10 is a diagram for explaining the operation of the node b.
FIG. 11 is a diagram for explaining the operation of the node a.

  In this embodiment, the representative node c80 leaves the ad hoc network that has established the trust space A described in the first embodiment with the node c80 as a representative node, and a new trust space B is reconfigured. The case will be described.

  First, the node c80 creates a leave notification message 831 that states that it is leaving the ad hoc network, and signs the private key c owned by only the node c80. Then, this leave notification message 831 is transmitted to all the nodes in the trust space A to which the node c80 belongs (see FIG. 7).

  Each node in the trust space A receives the leave notification message 831 from the node c80. Then, the signature of the leave notification message 831 is verified using the public key c distributed by the node c80, and it is confirmed that the leave notification message 831 is indeed transmitted from the node c80.

  Next, the node a 60, the node b 70, the node d 90, and the node e 100 that have received the leave notification message 831 from the node c 80 send an acquisition request message requesting the node c 80 to acquire the representative node right of the new trust space B.

  The operation will be described below using the node a60 as an example.

  The node a60 that has received the leave notification message 831 from the node c80 creates an acquisition request message 631 for the node c80. Then, in order to enable only the node c80 to read the acquisition request message 631, the acquisition request message 631 is encrypted with the public key c that can be decrypted only with the private key c owned by only the node c80. Further, in order to prove that the message is created by the node a60, a signature is made with the private key a. After performing the above processing, the node a60 transmits an acquisition request message 631 to the node c80 (see FIG. 8).

  Similarly, when the node b70, the node d90, and the node e100 receive the leave notification message 831 from the node c80, the above processing is immediately performed.

  When the above processing is performed at each node, the node c80 receives the acquisition request message from the node a60, the node b70, the node d90, and the node e100. At this time, the node c80 sets the message of the node that has transmitted the representative node right acquisition request message the earliest to be processed as described below. As an example, a case where the representative node right acquisition request message 631 of the node a60 created in the above description is first received will be described.

  The node c80 verifies the representative node right acquisition request message 631 received from the node a60 with the public key a of the node a60, and confirms that the corresponding message is surely transmitted from the node a60. Next, the representative node right acquisition request message 631 is decrypted using the private key c owned only by the node c80.

  When the node c 80 confirms that the acquisition request message 631 is a representative node right acquisition request message, the node c 80 creates a notification message 832 that states that the node a 60 is a new representative node of the trust space B. Then, the notification message 832 is encrypted using the public key of each node so that only each node can read the notification message 832. Next, in order to prove that the notification message 832 is surely transmitted by the node c80, a signature is performed using the secret key c. After executing the above processing, the node c80 transmits a notification message 832 to all the nodes in the trust space A (see FIG. 9).

  Next, the operation immediately after the node c30 leaves the ad hoc network will be described.

  The node b70, the node d90, and the node e100 send their public key certificates to the node a60, which is a new representative node notified from the node c80, in order to establish a new trust space B (see FIG. 10). In FIG. 10, the node b70 transmits the public key certificate b711 to the node a60.

  The node a 60 that has received the public key certificate sent from each node generates a public key certificate a 611 and a private key a for establishing the trust space B, similarly to the node c 30 of the first embodiment.

  Thereafter, the node a60 sends the public key certificate a611 generated by itself to the node b70, the node d90, and the node e100, and establishes a new trust space B (see FIG. 11).

  As described above, even if the representative node leaves, the next representative node is selected and a new trust space is established, so that there is an effect that safe data exchange can be continuously performed between the nodes. In addition, since the trust space is reconstructed based on the new trust information, there is an effect that the detached node cannot access the ad hoc network and steal information after leaving.

  In the above, the case where the representative node leaves has been described. Next, a case where the delegation node leaves will be described.

  When the delegation node leaves the network, it sends a leave notification to the representative node. When the representative node receives the withdrawal notification from the delegation node, the delegation node deletes the delegation node from the list of nodes that can be directly communicated. Also, if there is no response from the delegate node that sent the data, the representative node determines that the delegate node has left the network and deletes the delegate node from the list of nodes that can be directly communicated with It may be. The deleted delegation node is excluded from the trust space.

  In the above-described embodiment according to the present invention, a program or the like for executing the processing operation of the node device is recorded as data on a recording medium (not shown) such as a magnetic disk or a ROM of the node device. The data is read out and used to operate the node device. In this way, the data for operating the node device according to the present invention is recorded on the recording medium, and the function of the node device can be realized by installing this recording medium.

Diagram explaining the trust space between nodes The figure which shows the structure of the Example of this invention. The figure explaining operation of node a The figure explaining operation | movement of the node c The figure explaining operation of node a The figure explaining operation | movement of the node c The figure which shows the structure of the other Example of this invention. The figure explaining operation of node a The figure explaining operation | movement of the node c The figure explaining operation of node b The figure explaining operation of node a

Explanation of symbols

10 Node a
20 nodes b
30 node c
40 nodes d
50 node e
60 nodes a
70 node b
80 node c
90 node d
100 nodes e
111 Public key certificate a
121 Data a
311 Public key certificate c
321 data a
322 data a
323 data a
611 Public key certificate a
631 Acquisition request message 711 Public key certificate b
831 Departure notification message 832 Notification message

Claims (18)

An ad hoc network communication method in which a plurality of nodes form an ad hoc network and perform communication,
Means for selecting a representative node among the plurality of nodes;
Means for exchanging trust information between the representative node and another node (delegation node) to establish a trust space;
Means for relaying data transmission / reception between a transmission source delegation node and a transmission destination delegation node through the representative node and performing confidential communication based on the trust information;
An ad hoc network communication system characterized by this. The trust information is
Comprising a public key certificate,
The ad hoc network communication system according to claim 1. Means for creating a list of nodes that can be directly communicated by the own node;
Means for transmitting the created list (own list) to a node capable of direct communication;
Means for comparing the own list with a list (other list) received from another node;
Means for controlling the own node as a representative node when the number of nodes listed in the own list is large;
Means for controlling the own node as a delegation node when the number of nodes listed in the own list is small;
The ad hoc network communication system according to claim 1 or 2. Means for encrypting transmission data with the public key of the representative node and signing with the private key of the own node and transmitting to the representative node when the transmission source delegation node transmits data to the destination delegation node;
When the representative node receives data from the transmission source delegation node, the received data is verified with the public key of the transmission source delegation node and decrypted with the private key of the own node to make the reception data readable. Means for encrypting the extracted data with the public key of the destination delegation node, signing with the private key of the own node, and transmitting to the destination delegation node;
When the destination delegation node receives data from the representative node, means for verifying the signature of the received data with the public key of the representative node, decrypting it with the private key of the own node, and taking out the received data in a readable state With
The ad hoc network communication system according to claim 2 or 3, Means for the representative node to notify the delegation node of leaving the network and to select a next representative node from the delegation nodes;
The elected next representative node comprises means for exchanging trust information with the delegation node to establish a new trust space;
The ad hoc network communication system according to claim 1. An ad hoc network communication method in which a plurality of nodes form an ad hoc network and perform communication,
Selecting a representative node among the plurality of nodes;
A trust space is established by exchanging trust information between the representative node and another node (delegation node);
Relaying data transmission / reception between a source delegation node and a destination delegation node to the representative node and performing confidential communication based on the trust information;
An ad hoc network communication method characterized by the above. The trust information is
Contains a public key certificate,
The ad hoc network communication method according to claim 6. Create a list of nodes that can be directly communicated with
Send the created list (own list) to a node that can communicate directly,
Compare the own list with a list received from another node (other list),
When there are a large number of nodes listed in the local list, the local node is controlled as a representative node.
If the number of nodes listed in the own list is small, control the own node as a delegate node.
8. The ad hoc network communication method according to claim 6 or 7. When the source delegation node transmits data to the destination delegation node, the transmission data is encrypted with the public key of the representative node, signed with the private key of the local node, and transmitted to the representative node.
When the representative node receives data from the transmission source delegation node, the received data is verified with the public key of the transmission source delegation node and decrypted with the private key of the own node to make the reception data readable. Extracting the extracted data with the public key of the destination delegation node and signing it with the private key of its own node and sending it to the destination delegation node,
When the destination delegation node receives data from the representative node, the received data is verified with the public key of the representative node, decrypted with the private key of the local node, and the received data is taken out in a readable state.
The ad hoc network communication method according to claim 7 or 8. The representative node notifies the delegation node of the departure from the network and selects a next representative node from the delegation nodes;
The elected next representative node exchanges trust information with the delegation node to establish a new trust space;
The ad hoc network communication method according to claim 6. A node device that forms an ad hoc network and performs communication,
Means for creating a list of other nodes that can communicate directly;
Means for transmitting the created list (own list) to another node capable of direct communication;
Means for comparing the own list with a list (other list) received from another node;
Means for controlling the own node as a representative node when the number of nodes listed in the own list is large;
When the number of nodes listed in the own list is small, a means for controlling the own node as a delegation node;
Means for transmitting trust information to the representative node in the case of the delegation node;
Means for establishing trust space by exchanging trust information with the delegate node in the case of the representative node;
Means for performing secret communication based on the trust information in the case of the delegation node, relaying the representative node, and transmitting data to other delegation nodes;
A node device characterized by that. The trust information to be transmitted in the case of the delegation node is:
It includes the public key certificate of its own node,
The trust information transmitted in the case of the representative node is:
Including the public key certificate of its own node encrypted with the public key of the delegation node,
The node device according to claim 11, wherein: Means for encrypting data to be transmitted to the destination delegation node in the case of the source delegation node with the public key of the representative node, signing with the private key of the own node, and transmitting to the representative node;
In the case of a representative node, data received from the source delegation node is verified with the public key of the source delegation node, decrypted with the private key of the own node, and the received data is read out in a readable state. Means for encrypting with the public key of the destination delegation node, signing with the private key of the own node and transmitting to the destination delegation node;
Means for verifying the signature of the data received from the representative node in the case of the destination delegation node with the public key of the representative node, decrypting it with the private key of the local node, and taking out the received data in a readable state.
The node device according to claim 12, wherein: Means for notifying the delegation node of departure from the network in the case of the representative node and selecting a next representative node from the delegation nodes;
In the case of the delegation node, when elected as the next representative node, it comprises a means for controlling the own node as a representative node and exchanging trust information with the delegation node to establish a new trust space.
The node device according to claim 11, wherein: A program of a node device that forms an ad hoc network and performs communication,
In the node device
The ability to create a list of other nodes that can communicate directly,
A function of transmitting the created list (own list) to another node capable of direct communication;
A function of comparing the own list with a list (other list) received from another node;
A function to control the own node as a representative node when there are many nodes listed in the own list,
A function to control the own node as a delegate node when the number of nodes listed in the own list is small,
A function of transmitting trust information to the representative node in the case of the delegation node;
A function of establishing trust space by exchanging trust information with the delegate node in the case of the representative node;
A function of performing secret communication based on the trust information in the case of the delegation node and relaying a representative node to transmit data to another delegation node;
A program to realize A function in which the trust information to be transmitted in the case of the delegation node includes the public key certificate of the own node;
The trust information to be transmitted in the case of the representative node includes a function in which the public key certificate of the own node is encrypted with the public key of the delegation node;
The program of Claim 15 for implement | achieving. A function of encrypting data to be transmitted to the destination delegation node in the case of the source delegation node with the public key of the representative node, signing with the private key of the own node, and transmitting to the representative node;
In the case of a representative node, data received from the source delegation node is verified with the public key of the source delegation node, decrypted with the private key of the own node, and the received data is read out in a readable state. A function that encrypts with the public key of the destination delegation node, signs it with the private key of its own node, and sends it to the destination delegation node,
A function of verifying the signature with the public key of the representative node and decrypting the received data in a readable state by verifying the signature with the public key of the representative node in the case of the destination delegation node;
The program of Claim 16 for implement | achieving. A function of notifying the delegation node of leaving the network in the case of the representative node and selecting a next representative node from the delegation nodes;
A function for establishing a new trust space by controlling the own node as a representative node and exchanging trust information with the delegate node when elected as the next representative node in the case of the delegate node;
The program of Claim 15 for implement | achieving.

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