JP2008131564A - Credit rating method - Google Patents

Abstract

【Task】
PGP for calculating the degree of trust from the certificate of the neighbor, not the certificate authority, when the certificate authority is absent and the verification of the key certificate possessed by the communication terminal device is insufficient In the method, the load of collecting a certificate worthy of trust is large. In addition, what is evaluated as trustworthy and trustworthy in the actual system is a performance record, and such information is not reflected in the evaluation.
[Solution]
A wireless security system comprising a communication terminal device, and in one mode thereof, has the following three means.
(1) The communication terminal device has a function of monitoring the results of credit evaluation.
(2) The communication terminal apparatus evaluates different evaluation classes such as possessions and actual results.
(3) The communication terminal apparatus directly evaluates the evaluation target communication terminal apparatus, and at the same time, comprehensively evaluates it by taking into account the indirect evaluation of the evaluation target communication terminal apparatus by another communication terminal apparatus.
[Selection] Figure 10

Description

  The present invention relates to a technique for enhancing the security of an ad hoc network that is a temporary network configured by a mobile communication terminal device equipped with a relay function, and in particular, the trustworthiness of the other party is approximately measured by possession and performance. Evaluate and build network and community trust.

  The public key infrastructure (PKI) is widely used as the security infrastructure in the Internet, and the certificate authority is the source of trust. On the other hand, as wireless communications such as mobile phones and wireless LANs have become widespread in society, there is no need for fixed communication infrastructures, and mobile terminals (hereinafter referred to as terminals) are dynamically linked to multi-hops. A mobile ad hoc network (hereinafter referred to as an ad hoc network) that constructs a wireless network does not always have a connection point to the Internet, and therefore cannot use a certificate authority. In addition, it is practically difficult for all entities to receive authentication from a single certificate authority. In other words, in ad hoc networks, there is no method for confirming the location of responsibility between terminals that do not share common information, and it is possible to apply a trust model by a certificate authority implemented in the Internet or various IT systems. Have difficulty.

  As a security technology for ad hoc networks, when configuring a closed communication network that can communicate only between communication terminal devices belonging to a certain group, connection of communication terminal devices not belonging to the group is prevented, and communication data leakage is prevented. There exists the following patent document 1 as a secure routing to prevent. Non-Patent Document 1 discloses PGP, which is a technique that a neighbor certifies, not a specific person such as a certificate authority, as a technique for realizing a chain of trust by issuing a certificate.

JP 2005-278044 A "PGP-Cryptographic Mail and Electronic Signatures", Simson Garfinkel, Translated by Unitech, O'Reilly Japan, June 1996, p.235-236

  The technology disclosed in Patent Document 1 performs mutual authentication using public key cryptography and evaluates the trustworthiness on the assumption that communication terminal devices constituting a closed communication network mutually constitute a PtoP connection. On that basis, security information such as keys necessary for ensuring security is shared, but there is no certificate authority, and the verification of the certificate held by the communication terminal device is insufficient. Not mentioned. It is a big problem that the connection to the certificate authority is not possible because all the communication terminal devices that make up the network have the same attributes when used for a specific business that can limit the ad hoc network. Absent. However, it is a big problem in temporarily configuring a network community such as a street corner where certificates are issued from a plurality of certificate authorities.

  The technique disclosed in Non-Patent Document 1 discloses a scheme for calculating a trustworthiness based on a key certificate issued by a neighbor or an acquaintance, not a certificate authority. However, the burden of collecting a certificate worthy of trust is great. Moreover, it can be said that it is actual action results that trust and trust the other party in the actual system.

  The present invention has been made in view of such circumstances, and provides a method and a system for evaluating creditworthiness in consideration of different evaluation axes based on behaviors such as possession such as key certificate and transfer processing. . In addition, in the evaluation of trustworthiness, not only trust / do not trust, but also consider the intermediate value to improve the overall system availability.

That is, the present invention is a wireless security system including a communication terminal device, and in one aspect thereof, is characterized by the following three points.
(1) The communication terminal device has a function of monitoring the results of credit evaluation.
(2) The communication terminal apparatus evaluates different evaluation classes such as possessions and actual results.
(3) The communication terminal apparatus directly evaluates the evaluation target communication terminal apparatus, and at the same time comprehensively evaluates the evaluation target communication terminal apparatus in consideration of indirect evaluation by other communication terminal apparatuses.

  According to the above aspect, it is possible to evaluate the reliability of the target communication terminal device in a form that takes into account not only the conventional certificate evaluation but also the action results, etc., and a more flexible evaluation is possible. Therefore, it is possible to reduce the excessive security load on the target system and improve the system availability.

  A more specific aspect of the present invention is a method for evaluating the reliability of a wireless communication terminal device in an ad hoc network configured by a wireless communication terminal device equipped with a relay function, the reliability evaluation method comprising: A step in which the third wireless communication terminal apparatus grasps the operation results of the second wireless communication terminal apparatus; a step of determining the creditworthiness of the property of the second wireless communication terminal apparatus; From the operation results and the second wireless communication terminal device's possession of the second direct reliability, and the operation results and possessions for the second wireless communication terminal device calculated by the third wireless communication terminal device Transmitting the calculated integrated reliability to the first wireless communication terminal device; the first wireless communication terminal device serving as the second wireless communication terminal device serving as the third wireless communication terminal device; A step of acquiring integrated credit as a second indirect credit, a step of calculating an integrated credit from the direct credit and the indirect credit, and a step of acquiring the integrated credit And determining the reliability of the second wireless communication terminal device.

  Further, the credit rating evaluation method is characterized in that the first wireless communication terminal device calculates an integrated credit from the indirect credits of a plurality of third wireless communication terminal devices. In addition, the reliability evaluation method is characterized by determining whether or not the first and second wireless communication terminal devices can be connected based on the integrated reliability.

  According to the present invention, it is possible to reduce the security load and improve the availability of the target system.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing the concept of an ad hoc network in the present embodiment. In this figure, among a large number of unspecified communication terminal devices 10 (nodes), an ad hoc network in which communication terminal devices 10 (A1 to A6) belonging to a specific group are temporary closed communication networks by autonomous distributed wireless communication. Is configured.

  Specifically, the communication terminal device 10 (A1) is in a connected state with the communication terminal device 10 (A2 to A4), and the communication terminal device 10 (A4) is in a connected state with the communication terminal device 10 (A1, A5, A6). It is in. As will be described later, these are assumed to be connected when communication terminal apparatuses 10 belonging to a group are included in the respective wireless transmission ranges. Thereby, the communication terminal devices 10 (A1 to A6) can communicate with each other within the group. For example, the communication terminal device 10 (A2) is not connected to the communication terminal device 10 (A6), but can communicate with the communication terminal device 10 (A6) by relaying the communication terminal device 10 (A1).

  In this embodiment, when configuring such a group, for example, even when the communication terminal device 10 (B1) that does not belong to the group enters the wireless transmission range of the communication terminal device 10 (A1), ad hoc If the network has a track record such as forwarding, connection to the ad hoc network is permitted. In other words, in this embodiment, when connecting to an ad hoc network, not only mutual authentication based on key information etc. but also actions such as transfer are considered, enabling cooperative communication terminal devices to participate in the ad hoc network. .

  FIG. 2 is a block diagram illustrating an example of a hardware configuration of the communication terminal device 10 according to the present embodiment. As shown in the figure, the communication terminal device 10 includes an electronic device including a CPU 101, a memory 102, an input / output control device 103, a display device 104 such as a liquid crystal display, an input device 105 such as a pointing device and button keys, and a wireless module 106. Configured on a computer. Representative examples of the communication terminal device having such a configuration include a portable information processing device and a mobile phone. Of course, the hardware configuration of the communication terminal device 10 is not limited to this.

  The wireless module 106 is, for example, a wireless LAN standardized by IEEE 802.11: ANSI / IEEE Std 802.11 1999 Edition (http://www.ieee.org), but other wireless specifications, for example, portable You may communicate by the radio | wireless specification which uses a telephone network.

  Here, before explaining the functional configuration of the communication terminal device 10, an outline of the routing method in the ad hoc network will be explained. As for the ad hoc network routing method, standardization is being studied in IETF MANet (Mobile Ad Hoc Networking). Here, OLSR (Optimized Link State Routing) method, which is one of the proposed methods, will be described as an example. To do. The OLSR system is a so-called proactive routing system. The OLSR method is described in detail at http://www.ietf.org/rfc/rfc3626.txt. However, the present embodiment is not limited to this method, and can be applied to other proactive type, reactive type, hybrid type and other routing methods.

  In the OLSR system, each communication terminal apparatus 10 autonomously broadcasts a Hello message as a control message every 2 seconds, for example. Here, it is assumed that the Hello message includes a source identifier, a list of adjacent nodes capable of direct (1 hop) communication, and an MPR node list described below. The Hello message is received by another communication terminal device 10 existing within the transmission range. Mutual authentication is not mentioned here.

  Other communication terminal apparatus 10 that has received the Hello message refers to the Hello message and cannot directly communicate with itself, but there is a node that can communicate indirectly if it is forwarded to the source node of the Hello message. In that case, the source node is identified as an MPR node. Then, the node identified as the MPR node is added to the MPR node list and transmitted to the Hello message to be transmitted next.

  For example, in FIG. 1, the communication terminal device 10 (A2) cannot communicate directly with the communication terminal device 10 (A3), but indirectly communicates with the communication terminal device 10 (A1). Can be performed. In this case, the Hello message from the communication terminal device 10 (A1) identifies the communication terminal device 10 (A1) as an MPR node for the communication terminal device 10 (A2), and transmits from the communication terminal device 10 (A2). The identifier of the communication terminal device 10 (A1), for example, the IP address is included in the MPR node list of the Hello message to be executed.

  FIG. 4A is a diagram illustrating an exemplary format of a Hello message. In the example of this figure, the Hello message 400 is a message type 401 indicating that it is a Hello message, a transmission source node ID 402 for identifying the communication terminal device 10 that is the transmission source, a one-hop neighboring node list 403, and an MPR for itself. An MPR node list 404, which is a list of nodes, and a MAC (Message Authentic Code) 405 that guarantees the integrity of message contents are configured. As the source node ID 402, for example, an IP address can be used. In the 1-hop adjacent node list 403 and the MPR node list 404, each node included in the list can be identified by the IP address.

  Further, the communication terminal apparatus 10 that has become MPR autonomously broadcasts a Tc (Topology Control) message in addition to the Hello message, for example, every 5 seconds. Here, it is assumed that the Tc message includes an MPR node list that is a list of nodes that have become MPRs in the ad hoc network. Whether or not the own communication terminal device 10 has become MPR can be determined by referring to a Hello message sent from another communication terminal device 10.

  The MPR node that has received the Tc message transfers this Tc message to an adjacent node. At this time, if necessary, an own identifier such as an IP address is added to the MPR node list for transfer.

  In addition, each communication terminal apparatus 10 that has received the Tc message generates and updates a routing table based on the Tc message. Thereby, each communication terminal device 10 can grasp the topology of the ad hoc network, and controls the distribution of communication data in the ad hoc network according to the routing table.

  Here, the Tc message will be described. FIG. 4B is a diagram illustrating an example of the format of the Tc message. In the example of this figure, the Tc message 410 is a message type 411 indicating that it is a Tc message, a transmission source node ID 412 indicating a transmission source node of the Tc message, a generation node ID 413 indicating a generation source node of the Tc message, Tc It includes a direct node list 414 in which the message generation node is selected as MPR, and a MAC 418 that guarantees the integrity of the message contents.

  The communication terminal apparatus 10 that has become MPR can generate a Tc message based on information recorded in the ad hoc network management information storage unit 130.

  FIG. 3 is a block diagram illustrating an example of a functional configuration of the communication terminal device 10 according to the present embodiment. These functional units are virtually configured on the communication terminal device 10 as the CPU 101 performs processing according to the program code, data, and the like recorded in the memory 102.

  The program may be stored in advance in the memory 102, or when necessary, from a removable storage medium that can be used by the electronic computer, or a communication medium (wireless network or wired network not shown) It may be introduced from other devices via carrier waves or digital signals propagating over them).

  As shown in the figure, the communication terminal apparatus 10 includes a communication control processing unit 110, an ID storage unit 120, an ad hoc network management information storage unit 130, an authentication key storage unit 140, a policy storage unit 150, and a state monitoring processing unit 160. ing.

  The communication control processing unit 110 performs transmission / reception control processing, ad hoc connection control processing, authentication processing, key generation management processing, encryption processing, and the like. The ID storage unit 120 stores identification information for identifying the communication terminal device 10. As the identification information, for example, an IP address, a MAC address, or the like can be used. The ad hoc network management information storage unit 130 stores information necessary for configuring an ad hoc network. The authentication key storage unit 140 is a key used in mutual authentication processing between the communication terminal devices 10. For example, a key of a public key cryptosystem including a public key, a secret key, and a certificate authority public key is used. it can. A key of a common encryption method such as AES may be used. The policy storage unit 150 includes a key selection policy 151, an authentication policy 152, a key generation as policies that the communication control processing unit 110 refers to regarding transmission / reception control processing, ad hoc connection control processing, mutual authentication processing, key generation management processing, encryption processing, and the like. The policy 153 and the relaxation policy 154 are recorded.

  The ad hoc network management information storage unit 130 stores its own node information 131, MPR node information 132, direct node information 133, and indirect node information 134.

  FIG. 5A is a diagram illustrating an example of information managed by the own node information 131. The own node information 131 manages information about the communication terminal device 10 itself.

  In the example of this figure, the own node information 131 stores and manages the node ID 131a, the MPR flag 131b, the in-circle key 131f, and the in-circle key generation time 131g.

  The node ID 131a is an identifier of the communication terminal device 10, and for example, an IP address can be used. The MPR flag 131b is a flag indicating whether or not the MPR node 131b is an MPR node. The in-circle key 131f stores an in-circle key generated by itself. The in-circle key 131g stores the time when the in-circle key is generated.

  The own node information 131 may include other information, for example, status information indicating the state of the own node.

  FIG. 5B is a diagram illustrating an example of information managed by the MPR node information 132. In the MPR node information 132, information on MPR nodes existing in the ad hoc network is managed in a list format in units of MPR nodes. The MPR node is a node that is a generation source of the Tc message.

  In the example of this figure, the MPR node information 132 stores and manages the node ID 132a, the via MPR node 132b, and the hop count 132c.

  The node ID 132a is an MPR identifier, and for example, an IP address can be used. The via MPR node 132b is an identifier of an MPR node that requests transfer when data is transmitted to the MPR node. The hop count 132c stores the hop count from the communication terminal device 10 to the MPR node.

  The MPR node information 132 may include other information, for example, status information indicating the state of the MPR node.

  FIG. 6A is a diagram illustrating an example of information managed by the direct node information 133. In the direct node information 133, information on adjacent nodes that can directly communicate with the own node in one hop is managed in a list format in units of nodes. It is to be noted that the connection with the adjacent node is performed after authentication.

  In the example of this figure, the direct node information 133 stores and manages the node ID 133a, the MPR recognition flag 133b, the certification information 133c, and the inter-node key 133d.

  The node ID 133a is an identifier of an adjacent node, and for example, an IP address can be used. The MPR recognition flag 133b is a flag indicating whether or not the adjacent node regards the communication terminal device 10 as an MPR node. The certification information 133c is information regarding mutual authentication with the adjacent node. The inter-node key 133d is a key shared with its adjacent nodes. The inter-node key 133d is generated at the time of authentication.

  The direct node information 133 may include other information, for example, status information indicating a state between nodes.

  FIG. 6B is a diagram illustrating an example of information managed by the indirect node information 134. In the indirect node information 134, information on indirect nodes that can communicate indirectly with the own node is managed in a list format in units of nodes. Note that communication with the indirect node is performed via the MPR node.

  In the example of this figure, the indirect node information 134 stores and manages the node ID 134a, the routed MPR node 134b, the hop count 134c, and the certification information 134d.

  The node ID 134a is an identifier of an indirect node, and for example, an IP address can be used. The via MPR node 134b is an identifier of an MPR node that requests transfer when transmitting data to the indirect node. The via MPR node is a direct node, and there may be a plurality of via MPR nodes. The hop count 132c stores the hop count from the communication terminal device 10 to the indirect node. The certification information 133c is certification data such as MAC included in the Tc message transmitted by the communication terminal apparatus 10 that is an MPR node for the indirect node. As a result, the validity of the indirect node is indirectly guaranteed.

  The indirect node information 134 may include other information, for example, status information indicating the state of the indirect node.

  Note that the data configuration of the ad hoc network management information storage unit 130 differs depending on the routing method, and therefore corresponds to the routing method employed in the ad hoc network.

  Next, communication control processing in the communication terminal apparatus 10 will be described with reference to the flowchart of FIG.

  In this process, transmission of a Hello message and a Tc message is controlled by a timer. That is, if the transmission interval of the Hello message and the Tc message is 2 seconds and 5 seconds, respectively, the Hello timer is set to 2 seconds, the Tc timer is set to 5 seconds, and a timer up event occurs at each interval. (S101).

  Then, it waits for the occurrence of an event (S102). Examples of the event include a timer reception event and a message reception from another communication terminal device 10.

  When the communication terminal device 10 detects the occurrence of an event (S102: Y), it performs processing according to the event.

  That is, if the event that has occurred is a timer up event of the Hello timer, a Hello message is generated and broadcast distribution is performed (S103). The Hello message can be generated based on information recorded in the ad hoc network management information storage unit 130. Then, the Hello timer is reset (S104) and the next event is awaited (S102).

  If the generated event is a timer-up event of the Tc timer, the local node 131 of the ad hoc network management information storage unit 130 is referred to determine whether it is an MPR node (S105). As a result, if the node is not an MPR node, the Tc timer is reset (S107) and the next event is awaited (S102). On the other hand, in the case of an MPR node, a Tc message is generated and broadcast distribution is performed (S106). Then, the Tc timer is reset (S107) and the next event is awaited (S102).

  When the generated event is message reception from another communication terminal apparatus 10, it is determined whether or not the communication terminal apparatus 10 is an authenticated communication terminal apparatus 10 (S108). Whether or not the communication terminal device 10 has been authenticated can be determined by referring to the direct node information 133 in the ad hoc network management information storage unit 130.

  As a result, if the communication terminal device 10 has not been approved (S108: N), it is checked whether the message is a Hello message (S109). If it is not a Hello message, the received message is discarded as a message from the unapproved communication terminal device 10 (S112). On the other hand, if it is a Hello message, an authentication process is performed with the unapproved communication terminal device 10 (S110). The authentication process will be described in detail with reference to FIG.

  If the authentication process is completed (S108), the message is processed (S115). When the generated event is message reception from another authenticated communication terminal device 10 (S108: Y), processing corresponding to the message is performed with reference to the message type (S115).

  That is, if the message is a Hello message, the ad hoc network management information storage unit 130 is updated as necessary. If the message is a Tc message, the ad hoc network management information storage unit 130 is updated as necessary. If the message is an MPR node, the received Tc message is transferred to an adjacent node.

  When the received message is a data communication message, the transmission destination of the control information of the data communication message is referred to. When the transmission destination indicates another communication terminal device 10, the ad hoc network management information storage unit 130 is referred to request transfer to another node, and the transmission destination specifies its own communication terminal device 10. If so, the data communication message is captured.

  If it is the timing of periodic authentication, the process returns to the authentication process (S110). If the reliability of the target communication terminal device 10 is lower than the threshold defined in the authentication policy in the authentication process (S110), the connection is terminated and the information in the management information storage unit 130 is updated.

  Periodic authentication is performed in accordance with an authentication policy, but authentication can be started autonomously at regular timing or when each terminal recognizes that it is necessary. These rules can be recorded in the policy storage unit 150 as an authentication policy or a re-authentication policy. The authentication policy can further record an interval time for performing re-authentication, the number of times of authentication continuation, an authentication level, and the like. Here, in FIG. 9C described later, evaluation points T1, T2, and T3 are defined, and authentication is performed at this timing.

  FIG. 8A is a diagram showing an example of an authentication message exchanged at the time of authentication. In the example of this figure, the authentication message 500 is a message type 501 indicating that it is an authentication message, a sender IP address 502 for identifying the communication terminal device 10 that is the sender of the authentication message, and the communication terminal device 10 that is the authentication partner. Authentication partner IP address 503 for identifying the user, a random number 504 generated by the communication terminal device 10 of the transmission source, a sender public key certificate 505, and an authentication code 506. Here, the authentication code 506 is a code generated by the transmission source communication terminal device 10 using the secret key information with respect to the random number generated by the authentication partner.

  If the communication partner cannot be authenticated as a result of the mutual authentication (S111: N), it is determined that the communication terminal device 10 is out of the group and the connection to the ad hoc network is not permitted, and the received Hello message is discarded. (S112). Thereby, it can prevent that the communication terminal device 10 outside a group connects to an ad hoc network.

  As a result of the authentication, if the communication partner can be authenticated (S111: Y), it is assumed that the communication terminal device 10 is included in the group, and the connection to the ad hoc network is permitted. Exchange of keys and in-circle keys is performed (S113). Also, necessary information is registered in the ad hoc network management information storage unit 130.

  FIG. 8B is a diagram illustrating an example of a key exchange message exchanged after authentication. In the example of this figure, the key exchange message is a message type 511 indicating that it is a key exchange message, a sender IP address 512 for identifying the communication terminal device 10 that is the transmission source of the key exchange message, and transmission of the key exchange message. It includes a receiver IP address 513 for identifying the previous communication terminal device 10, an inter-node key 514, an intra-circle key 515, an inter-node re-authentication key 516, and a MAC 517 that guarantees the integrity of the message content. .

  Among these, the inter-node key 514, the in-circle key 515, the inter-node re-authentication key 516, and the MAC 517 are encrypted using, for example, the public key of the communication terminal device 10 on the receiving side.

  Thereby, the in-circle key can be safely distributed to the communication terminal apparatuses 10 belonging to the group existing within the transmission possible range.

  FIG. 9 shows the policy.

  FIG. 9A illustrates an example of an authentication policy at the time of authentication processing. In the example of this figure, the authentication policy 151 indicates the weighting of evaluation in the credit evaluation. A direct evaluation weight (D) 151a indicating a weight of direct evaluation, an indirect evaluation weight (R) 151b indicating a weight of indirect evaluation, a weight (DC1) 151c of a direct evaluation authentication class 1 indicating a weight of authentication class 1 in the direct evaluation, Weight of direct evaluation authentication class 2 (DC2) 151d indicating weight of authentication class 2 in direct evaluation, Weight of indirect evaluation authentication class 1 (RC1) 151e indicating weight of authentication class 1 in indirect evaluation, Authentication class 2 in indirect evaluation The weight 151f of the indirect evaluation authentication class 2 (RC2) indicating the weight of In the calculation of the integrated reliability, the direct evaluation and the indirect evaluation are calculated by reflecting the weight of D: R. Similarly, the calculation of reliability by direct evaluation indicates that the evaluation results of evaluation class 1 and evaluation class 2 are calculated by reflecting the weight of DC1: DC2.

  The authentication class 1 is a property or the like, and the authentication class 2 is an action result. In an ad hoc network, for example, the property is a key set, and the action result is a transfer result. In order to prevent unauthorized use of the network, an integrated evaluation value is calculated, evaluated and authenticated as to whether or not the other party is worthy of connection prior to connection. Depending on the situation, disconnect.

  FIG. 9B is a diagram illustrating an example of evaluation judgment of an authentication policy at the time of authentication processing. In the example of this figure, the authentication policy 151 includes a condition 1511a for evaluating the trustworthiness of the key set as high, a condition 1511b for evaluating the trustworthiness of the key set as medium, a condition 1511c for evaluating the trustworthiness of the key set as low, This includes a condition 1511d for evaluating that the creditworthiness by the transfer is high, a condition 1511e for evaluating the trustworthiness by the transfer record as medium, and a condition 1511f by which the trustworthiness by the transfer record is evaluated as low.

  The validity of the key set is realized by, for example, exchanging a plurality of messages as described in detail in ISO / IEC 9798, but the authentication process is performed when challenge / response authentication is performed. It is comprehensively determined from the numerical validity of the generated authentication data, the freshness of the CRL associated with the execution confirmation of the key certificate, or the issuer information of the public key certificate.

  FIG. 9C is a diagram illustrating an example of a threshold value that is an evaluation judgment of the authentication policy at the time of the authentication process. In the example of this figure, the authentication policy 151 has an integrated evaluation value threshold 1512a at the evaluation point T1, and an evaluation point threshold 1512b at the evaluation point T2 and an evaluation point T3. And the integrated evaluation value threshold value 1512c. Here, three points T1, T2, and T3 are described, but the number is not limited to three points.

  FIG. 10 shows the authentication process (S110) in FIG. 7 of the communication control process in the communication terminal apparatus 10. Here, the communication terminal device 10 (A4) in FIG. 1 shows processing of the communication terminal device 10 (A4), taking as an example a case where wireless communication is established between the communication terminal devices 10 (A3) and the reliability is evaluated. . The communication terminal device 10 (A4) directly evaluates the reliability of the communication terminal device 10 (A3) (S1001). Next, the communication terminal device 10 (A4) obtains the reliability of the communication terminal device 10 (A1) with respect to the communication terminal device 10 (A3), and uses this as the reliability by indirect evaluation (S1002). An integrated credit rating is calculated from the direct evaluation value and the indirect evaluation value (S1003). If the integrated reliability is higher than the threshold defined in the policy, it is determined that the communication terminal device 10 (A4) has authenticated the communication terminal device 10 (A3).

  Communication terminal apparatus 10 (A4) calculates target evaluation value DP1 of communication terminal apparatus 10 (A1) with respect to communication terminal apparatus 10 (A3) as follows.

DP1 = (DC1 xdc1 + DC2 xdc2) / (DC1 + DC2)
However,
xdc1 Direct evaluation value obtained in class 1
xdc2 Direct Evaluation Value Obtained in Class 2 Here, xdc1 is obtained as a result of FIG. The acquisition of xdc2 will be described later.

  Communication terminal device 10 (A4) calculates indirect evaluation value RP1 with respect to communication terminal device 10 (A3) as follows.

RP1 = (RC1 xrc1 + RC2 xc2) / (RC1 + RC2)
However,
xrc1 Indirect evaluation value obtained in class 1
xrc2 Indirect evaluation value obtained in class 2
xrc1 and xrc2 are provided to the communication terminal apparatus 10 (A4) by the communication terminal apparatus 10 (A1) in response to an inquiry from the communication terminal apparatus 10 (A4).

  Moreover, the communication terminal device 10 (A4) calculates the integrated reliability TP with respect to the communication terminal device 10 (A3) as follows.

TP = (D DP1 + R RP1) / (D + R)
If the corresponding data cannot be acquired, DC1, DC2, RC1, and RC2 are set to 0, respectively.

  FIG. 12 is a diagram illustrating an example of calculation of the direct evaluation value. In the example of this figure, the direct evaluation value 1200 includes the transfer evaluation value 1201 and the key set evaluation value 1202 in the configuration, and the DC1 is set to 1.0 for high, 0.5 for medium, and 0.1 for low. This is an example of the calculated direct credit rating, where 1 and DC2 are 2.

  FIG. 11 shows processing of the state monitoring processing unit 160 in the communication terminal device 10. Here, communication terminal device 10 (A4) in FIG. 1 transmits message A to communication terminal device 10 (A1) (S1101), and communication terminal device 10 (A1) transfers message A (S1102). The terminal device 10 (A4) updates the transfer record counter of the communication terminal device 10 (A1). The transfer record counter is managed by the certification information 133c and 134d, and the record is evaluated quantitatively. Here, the transfer result counter is described, but the message to be transferred and the transferred result are managed as the transfer rate. The communication terminal device 10 (A4) can monitor not only the message transmitted by the communication terminal device 10 (A4), but also, for example, there is a connection between the communication terminal device 10 (A4) and the communication terminal device 10 (A3). In this case, it is possible to monitor whether the communication terminal apparatus 10 (A1) has transferred the message of the communication terminal apparatus 10 (A3).

  Here, xdc2 is a transfer performance rate.

  The communication terminal device 10 (A1) provides the communication terminal device 10 (A4) with the authentication policy of the communication terminal device 10 (A1) together with the evaluation value of the communication terminal device 10 (A3), and the communication terminal device 10 (A4). ) May consider the authentication policy of the communication terminal device 10 (A1) when calculating the indirect evaluation value of the communication terminal device 10 (A1).

    Here, only the evaluation value of the communication terminal device 10 (A1) is considered as the indirect evaluation value of the communication terminal device 10 (A3). However, the indirect evaluation value collected from the plurality of communication terminal devices 10 is calculated. May be. For example, an average or maximum value of a plurality of communication terminal devices 10 may be employed.

  As described above, according to the present embodiment, each communication terminal device can comprehensively evaluate the possession (key set) and action result (transfer) of the communication terminal device to be evaluated.

It is a figure which shows the concept of the ad hoc network in this embodiment. 2 is a block diagram illustrating an example of a hardware configuration of a communication terminal device 10. FIG. 2 is a block diagram illustrating an example of a functional configuration of a communication terminal device 10. FIG. (A) is a figure which shows an example of the format of a Hello message. (B) is a figure which shows an example of the format of Tc message. (A) is a figure which shows an example of the information managed with the own node information 131. FIG. (B) is a figure which shows an example of the information managed by the MPR node information 132. (A) is a figure showing an example of information managed by direct node information 133. FIG. 6B is a diagram illustrating an example of information managed by the indirect node information 134. It is a flowchart explaining the communication control process in the communication terminal device. (A) is a figure which shows an example of the authentication message exchanged in the case of mutual authentication. (B) is a figure which shows an example of the key exchange message exchanged after mutual authentication. (A) is an authentication policy, (b) is an evaluation judgment of an authentication policy, (c) is a figure which illustrates the threshold value used as an evaluation judgment. It is a flowchart explaining the authentication process in the communication control process of FIG. It is a flowchart explaining the state monitoring process part 160 in the communication terminal device 10. FIG. It is a figure which shows an example of calculation of a direct evaluation value.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Communication terminal device 101 ... CPU, 102 ... Memory, 103 ... Input / output control device, 104 ... Display device, 105 ... Input device, 106 ... Wireless module, 110 ... Communication control processing part, 120 ... ID memory | storage part, 130 ... ad hoc network management information storage unit 131 ... own node information 132 ... MPR node information 133 ... direct node information 134 ... indirect node information 140 ... authentication key storage unit 150 ... policy storage unit 160 ... status monitoring Processing part

Claims (3)

A method for evaluating the reliability of a wireless communication terminal device in an ad hoc network composed of wireless communication terminal devices equipped with a relay function,
A step in which the first and third wireless communication terminal devices grasp the operation results of the second wireless communication terminal device, a step of determining the credit quality of the property of the second wireless communication terminal device, and a second wireless communication Calculating the second direct reliability from the operation results of the communication terminal device and the property of the second wireless communication terminal device;
A step of transmitting, to the first wireless communication terminal device, the integrated reliability calculated from the operation results for the second wireless communication terminal device calculated by the third wireless communication terminal device and the property;
A first wireless communication terminal device acquiring the integrated creditworthiness of the second wireless communication terminal device as a second indirect creditworthiness by the third wireless communication terminal device;
The first wireless communication terminal device calculates an integrated credit from the direct credit and the indirect credit;
And a step of determining the credit quality of the second wireless communication terminal device from the integrated credit quality. The credit rating method according to claim 1,
The credit evaluation method, wherein the first wireless communication terminal device calculates an integrated credit from indirect credits of a plurality of third wireless communication terminals. The credit rating method according to claim 1 or 2,
A reliability evaluation method comprising: determining whether or not the first and second wireless communication terminal devices can be connected from the integrated reliability.

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